This weekend, the people at Valve treats us to another free weekend. This time, it's UT3 Black. It is free to play until Sunday, and you get 50% off if you choose to buy it (offer until June 7!). See this message for details: http://cdn.store.steampowered.com/message/19285217748367359 .
To directly install UT3, enter steam://run/13210 into your address bar.
Bonus: you get a free multiplayer serial number when you install. No idea how long it's valid for, but it's guaranteed to work for the free weekend.
Sidenote: This game was available for preloading since Tuesday, but everytime I tried to Steam told me that its servers was too busy to handle the request. Either Valve screwed up or this game is extremely popular.
