In case you aren't on the Flickr API mailing list and you've been itching to use the new collections feature in your API application, Eric Costello responded to someone asking when "collections" will be available in the API:
Probably months. Could be sooner, but we have a whole lot of higher priority things going on right […]
The awesome guys at Flickr just added options to the "sort" parameter of the flickr.photos.search method that allow you to sort by "Interestingness". Right now, this is undocumented on their site but it should be out some time on 10/21. In case you want to start using this right away, if you specify […]