Steam has a deal going with Nvidia right now that any Steam user should be able to redeem (Steam is free and easy to setup)- they're giving away a demo of the first 11 levels of Portal, Half-Life 2: Deathmatch, Half-Life 2: Lost Coast, and most importantly, Peggle Extreme :P

HL 2: DM usually costs five dollars in the Steam store, and Lost Coast about the same.

I'm personally having a lot of fun with it. At first I didn't play it, because I was new to it and didn't know much of how to play it, but last night I played it with a friend of mine in a small game and together we rocked the scoreboard. :D

Check it out here. I hope to play a game with you soon!