Miriam Salpeter, Chris Brogan, Stephanie Lloyd, Todd Schnick, & Bert DuMars

As defined by Urban Dictionary, Tweetup:

1. An organized or impromptu gathering of people that use Twitter. (A meet up of people that ‘tweet’ using Twitter.)

2. A gathering of nerds attempting social contact, likely for the first time. Usually disintegrates into everyone running to the nearest [...]