Greetings, fellow GOGers,

I happen to have a few spare invites for Evolve, which is in closed beta. Evolve is basically a mix between hamachi/tunngle for the easy VPN thingy, and Steam for the in-game overlay and community stuff. Here's the website.

I find the overlay pretty useful : it contains an instant messenger with MSN/GTalk/Jabber compatibility, and a tabbed, flash-enabled web browser. When you close your game, the evolve windows that you opened in-game remain open, and you can carry them into the next game (or just use them from the windows desktop).
Keep in mind it's still a beta, so it's a bit rough around the edge, but there's great potential IMHO. If you're interested, drop me a PM containing your email and I'll send you the invite.