I recently joined Pownce, a social network that enables users to send messages, links, files, and events to friends and groups of friends.
I find it similar to twitter except the posts are longer and more versatile. Twitter and Pownce are in the same class of social network, called micro-blogging. Micro-blogging is basically a short-text based message system in which users update their status via a variety of platforms.
[Cont. 1/29/08] I just received my first event! This service is kick! I am finding it more pleasant to work with as I add more connections and am able to view feedback of other Powncers. It has also served as a good replacement to my error-filled twitter desktop app. This does not mean I have forgot about twitter and all the twitterers out there, it just means I have been concentrating on Pownce a bit more.
Good job Pownce dev team!!!