Paper-based document logging

1. A method comprising:

sequentially examining identified locations of a document in a prioritized ordering of a list that contains a plurality of document locations that are statistically more likely to contain a machine readable code than document locations that are not in the list, wherein each identified location in the prioritized ordering of the list corresponds to a particular region on a page of the document, and wherein the prioritized ordering of identified locations to be examined is prioritized based on a determined layout of content within the document;

scanning bits of the document;

generating, with a processor, a cryptographic hash from the scanned bits of the document, the cryptographic hash identifying the document for document logging;

converting the cryptographic hash into the machine readable code;

rewriting the document with the code contained in a region of the document corresponding to a first identified location in the prioritized ordering of the list of identified locations where the region is empty; and

using the cryptographic hash as an identifier to a document log with one or more sets of metadata entries associated with the document, wherein each of the one or more sets of metadata entries are sets of related user generated comments that are associated with the document.

2. The method defined in claim 1 , wherein scanning bits of the document occurs when the code is not at the one or more locations.

3. The method defined in claim 2 further comprising storing scanned bits corresponding to content of the document and the hash in a database.

4. The method defined in claim 1 further comprising selecting a plurality of locations for the code on the document.

5. The method defined in claim 4 wherein the plurality of locations are selected based on one or more of a group consisting of size, probability of ordinary documents filling that area, and an aesthetic placement consideration.

6. The method of claim 1 , wherein at least one user generated comment from the sets of user generated comments includes a comment directed to the document that includes a link that points to a related document and corresponding document log.

7. A non-transitory computer-readable storage medium with instructions stored thereon which, when executed by a system, cause the system to perform a method comprising:

sequentially examining identified locations of a document in a prioritized ordering of a list that contains a plurality of document locations that are statistically more likely to contain a machine readable code than document locations that are not in the list, wherein each identified location in the prioritized ordering of the list corresponds to a region on a page of the document, and wherein the prioritized ordering of identified locations to be examined is prioritized based on a determined layout of content within the document;

scanning bits of a document;

generating a cryptographic hash from the scanned bits of the document, the cryptographic hash identifying the document;

converting the cryptographic hash into a the machine readable code;

rewriting the document with the code contained in a region of the document corresponding to a first identified location in the prioritized ordering of the list of identified locations where the region is empty; and

using the cryptographic hash as an identifier to a document log with one or more sets of metadata entries associated with the document, wherein each of the one or more sets of metadata entries are sets of related user generated comments that are associated with the document.

8. The computer-readable storage medium in claim 7 , wherein scanning bits of the document occurs when the code is not at the one or more locations.

9. The computer-readable storage medium in claim 8 wherein the method further comprises storing scanned bits corresponding to content of the document and the hash in a database.

10. The computer-readable storage medium in claim 7 wherein the method further comprises selecting a plurality of locations for the code on the document.

11. The computer-readable storage medium in claim 10 wherein the plurality of locations are selected based on one or more of a group consisting of size, probability of ordinary documents filling that area, and an aesthetic placement consideration.

12. A method comprising:

sequentially examining identified locations of a document in a prioritized ordering of a list that contains a plurality of document locations that are statistically more likely to contain a machine readable code than document locations that are not in the list, wherein each identified location in the prioritized ordering of the list corresponds to a particular region on a page of the document, and wherein the prioritized ordering of identified locations to be examined is prioritized based on a determined layout of content within the document;

generating, with a processor, a machine readable code whose contents are associated with document content when the code is not found in a location specified in the list, wherein the machine readable code encodes a cryptographic hash that is computed from the contents of the document and identifies the document;

creating a paper version of the document with the machine readable code contained in a region of the paper version of the document corresponding to a first identified location in the prioritized ordering of the list of identified locations where the region is empty; and

using the cryptographic hash as an identifier to a document log with one or more sets of metadata entries associated with the document, wherein each of the one or more sets of metadata entries are sets of related user generated comments that are associated with the document.

13. A method comprising:

scanning bits of a document;

detecting, with a processor, a machine readable code in scanned bits of the document, wherein the machine readable code is a code that has been added to a region of the document corresponding to a first identified location in a prioritized ordering of a list of identified locations where the region is empty, and wherein the machine readable code encodes a cryptographic hash that is computed from contents of the document and identifies the document for document logging, and the machine readable code is detected by sequential examination of identified locations of the document in the prioritized ordering of the list that contains a plurality of document locations that are statistically more likely to contain the machine readable code than document locations that are not in the list, wherein each identified location in the prioritized ordering of the list corresponds to a particular region on a page of the document, and wherein the prioritized ordering of identified locations examined is prioritized based on a determined layout of content within the document;

gaining access to a document log using contents of the machine readable code as an identifier, wherein the contents of the machine readable code include a cryptographic hash computed from the scanned bits of the document, and wherein the document log includes one or more sets of metadata entries associated with the document, wherein each of the one or more sets of metadata entries are sets of related user generated comments that are associated with the document.

14. The method defined in claim 13 further comprising verifying scanned bits against bits stored in a database to ensure that the document is pointing to the document log.

15. The method defined in claim 13 wherein the list of potential locations is scanned in a predetermined order based on decreasing statistical likelihood that a particular potential location is likely to contain the machine readable code.

16. A non-transitory computer-readable storage medium with instructions stored thereon which, when executed by a system, cause the system to perform a method comprising:

sequentially examining identified locations of a document in a prioritized ordering of a list that contains a plurality of document locations that are statistically more likely to contain a machine readable code than document locations that are not in the list, wherein each identified location in the prioritized ordering of the list corresponds to a particular region on a page of the document, and wherein the prioritized ordering of identified locations to be examined is prioritized based on a determined layout of content within the document;

scanning bits of the document;

detecting the machine readable code in scanned bits of the document, wherein the machine readable code is a code that has been added to a region of the document corresponding to a first identified location in the prioritized ordering of the list of identified locations where the region is empty, and wherein the machine readable code encodes a cryptographic hash that is computed from contents of the document and identifies the document for document logging; and

gaining access to a document log using contents of the machine readable code as an identifier to the document log, wherein the document log includes one or more sets of metadata entries associated with the document, wherein each of the one or more sets of metadata entries are sets of related user generated comments that are associated with the document.

17. The computer-readable storage medium in claim 16 wherein the method further comprises verifying scanned bits against bits stored in a database to ensure that the document is pointing to the document log.

18. The computer-readable storage medium in claim 16 wherein the list of potential locations is scanned in a predetermined order.

19. A method comprising:

sequentially examining, with a processor, identified locations of a document in a prioritized ordering of a list that contains a plurality of document locations that are statistically more likely to contain a machine readable code than document locations that are not in the list, wherein each identified location in the prioritized ordering of the list corresponds to a particular region on a page of the document, and wherein the prioritized ordering of identified locations to be examined is prioritized based on a determined layout of content within the document;

scanning bits of the document if the machine readable code is not found at the one or more locations;

comparing the document image corresponding to scanned bits of the document against stored document images in a memory; and

obtaining a cryptographic hash associated with a stored document image that matches the document image corresponding to the scanned bits if a match is found, the cryptographic hash that is computed from contents of the stored document and identifies the document for document logging, wherein the cryptographic hash is an identifier to a document log for the stored document image, and wherein the document log includes one or more sets of metadata entries associated with the stored document, wherein each of the one or more sets of metadata entries are sets of related user generated comments that are associated with the document;

computing a cryptographic hash of the document image corresponding to the scanned bits if a match is not found in the memory; and

storing the document image corresponding to the scanned bits and the cryptographic hash in the memory, wherein the cryptographic hash is added to a region of the document image corresponding to a first identified location in the prioritized ordering of the list of identified locations where the region is empty.