n. A real world meeting between two or more people who know each other through the online Twitter service.
2008
People keep coming, conversations are perpetually on, someone leaves, and someone else joins in. You chat with your friends and acquaintances regularly and ever so often you also meet one of their friends. You join into their conversations and make new friends in the process. Someone you didn't know earlier reaches out to connect; you do the same when you want to reach out. This café is virtual, but the people are real and they do meet up often — at work, at parties, at Tweetups (offline group meets of Tweople, as Twitter users are called).
2007
Twitter has been taken up so exuberantly by the connected community that it's now used by the MTV Music Video Awards, presidential candidate John Edwards, and even some news organizations and fire departments to communicate their urgent messages. Its own vocabulary has even emerged: As mentioned earlier, a Twitter post is called a "tweet," and "tweetups" have taken place where "tweeps" have met up in the real world for social gatherings. You can find a glossary of Twitter terminology at the Twitter Fan Wiki.
2007 (earliest)
This is a blog entry that was inspired by a face-to-face meeting between two bloggers who connected via Twitter. What would you call that? A Twittermeet? A Tweetup? Cast your vote in the comment section.