Like to chat and tweet? Try Qvaq. It's a brand new and very neat web app, made by Robert Birming (a Neatoramanaut and fellow blogger at Geek Alerts) and Martin Lindkvist, that makes discussion and collaborations in real time fun and easy.
With Qvaq, you can discuss your favorite topics with others (either by joining an existing group like the Neatorama group and Guess The Movie or by starting your own). You can add photos and video clips, chat privately or publicly, and so on. None of these are new features - Martin acknowledged that IRC has been around since the 80's - but what they've done is create a smoothly integrated set of functionalities that just flow easily. Qvaq is fun to use :)
Give it a try - I'll be at the Neatorama group there off and on today. Come and say hello: Link