I would love it if Twitter would develop an equivalent to Facebook's FQL, Yahoo's YQL, Amazon's SimpleDB, or Google's GQL (used for app engine data storage).
Basically an abstracted SQL-like query engine for doing queries and getting back data the data you want using virtual tables of different data twitter serves up. You could do something basic like: SELECT StatusID, UserID, Text FROM StatusUpdates as S WHERE S.UserID in (SELECT UserID FROM SocialGraph WHERE FollowerUseringID = MYUSERID) and S.StatusID > LASTID ORDER BY S.StatusID DESC LIMIT 200 to get a basic user's following timeline or whatever. From there you can build on from that and get a bit more complex. It could even build on from just query syntax to modify and destructive calls. Maybe something like: DELETE FROM StatusUpdates WHERE StatusID = 200102; or: INSERT INTO StatusUpdates(text,replyToStatusID,replyToUserID) VALUES ('@johnsmith hello',123601020,235133); or: UPDATE StatusUpdates SET favorite = TRUE WHERE StatusID = 123601020; You could do it where you do an HTTP get/post with a query like above to twitter's rest api, and the results could come back as JSON or XML or whatever. Some concepts like this could be done in a local side wrapper (like I've seen a SQL bridge for MSSQL for twitter on here a while back) but it would be awesome if these were processed twitter server side. If done right, it can save on overhead on both twitter and from the client side. Like in one case I have where I'm hitting the following timeline, I'm missing something out of the user structure that you get back from that, so I turn around and do another user call on user for each tweet to get that data. Half the data I get back in both cases don't use on both calls but it would be awesome to be able to get that data in one call. A lot to consider around optimization and limits and a bit of work to build it but I think something like that would be really useful. Zac