Newly-launched Snimmer has a glimmer of a great idea, but don't test it unless you are very careful and/or prepared to apologize to your instant messaging contacts all evening. I wasn't.
Like Meebo and eBuddy, Snimmer is a web-based instant messaging service. Unlike those services, however, Snimmer is also a social network, allowing users to upload bio information, photos, and other information about themselves and share it with others. If you find people you want to chat with on the service, you can create a chat room on the fly using Jabber (or GTalk) - they do not need to have previously been added to your instant messaging friends list.
When you use the service and sign on there is an opt-out to tell all your friends about the service. I caught it the first time and unchecked it, but on a second login I forgot and all of my GTalk friends were IMed with a message about Snimmer. I then spent thirty minutes apologizing to everyone who IMed me with "WTF" or something similar.
I like the idea a lot - looking at people's pictures and other information while chatting with them is a great idea. Try it if you dare - but don't say I didn't warn you.