Tweetvite allows users to create and find tweetups in the user's area. Tweetvite's features include customizable invites, tracking tweets and retweets about the tweetup, and listing of events for others to find.
The Tweetvite API is currently read-only. The API allows users to search and retrieve event information (guestlists, comments) and user profiles. Tweetvite plans to launch an API that users can write in the future.