Summer may have just officially started just a few days ago but the Steam PC game download site has already launched its big summer sales period. From now until July 4 you can get some big savings on a ton of games including 25 percent off all Rockstar Games and 2K Games titles, 33 percent off all Ubisoft games, and 75 percent of all 1C Company games (just to name a few).

In addition to all of the "regular" sales, Valve will put a number of games and game packs on the price chopping block for one day only. From now until 1 pm Eastern time Friday you can get the games listed below at these prices:

• Killing Floor - $5
• Trine - $4
• Counter-Strike Source- $6.80
• Dirt 2 - $10
• Overlord Complete Pack (3 Game Bundle) - $4.50
• Aion Standard Edition - $19.99
• Unreal Deak Pack (5 Game Bundle) - $13.50
• BioShock 2 - $14.99