Flash buzz-site of the moment:
Red Universe is an interactive avatar chat in Flash, where you can explore the good-looking world while talking with others.
Little advertisement:
If you’d like to do something similar, look at www.madarco.net. If there aren’t other users connected (likely), open it in two tabs and move the mouse to interact, type to talk.
I’ll release my quick-and-dirty flash socketserver soon, it is written in perl and run on every Dreamhost hosting.