I started following Criterion Games on Twitter recently. I have not been on Twitter all that long myself, but it is a great way to quickly keep in touch with friends all around the world..
anyway, back to CG on Twitter... this morning CG's front page news was all about how they now have Twitter accounts. You can sign up to Twitter and follow Criterion Games, Matt Webster, Pete Lake and Craig Sullivan. Since this was announced on the Criterion Games website their followers have gone up to 500+ and lots of names from the forums have now joined Twitter.