I was soliciting input on the status of the API section of the developers guide
in regards to its completeness for Drupal 7, today on IRC.
I noticed that several pages in the File API section (that's a new API for Drupal 7) were flagged as "incomplete". It would be good to complete those pages.
Also, chx did a quick review and posted this in IRC in regards to the file API section:
While this http://drupal.org/node/877214 mentions somewhat that "there is normally no need to check where on the filesystem the "public" file directory is" which is true, and yet sometimes you must use what was file_directory_path() which is now variable_get('file_public_path', conf_path())