FriendFeed Social media aggregator released version 2 of FriendFeed API with number of compelling new features:

-Real-time APIs - utilize long polling to get feeds in real-time, including search!
-Flexible sharing options - Direct message users. Share to multiple feeds.
-File attachments - Attach images, pdfs, spreadsheets, etc.
-OAuth support - Register your application now.
-Simplified response format, include a list of possible commands on every feed, entry, and comment so you don't have to do the detective work.

More info: FriendFeed Blog