We've already had a lot of downloadable PC game sales this week so what's a few more between friends?

Steam has announced that it will be offering titles from casual game publisher PlayFirst on its service. From now until August 19 all 10 PlayFirst games via Steam will have a price cut of 10 percent. Also the recent platform action game Trine has a 25 percent price cut until August 19 Direct2Drive has the same price cut offer for Trine.

Meanwhile, GamersGate has announced that the 2008 released first person shooter S.T.A.L.K.E.R. Clear Sky gets a big 50 percent price cut from now until Sunday.

Finally the retail site GoGamer.com has a number of PC games on sale from now until 3 am ET Saturday, including the original Operation Flashpoint for just $5.90, Vietcong 2 for $4.90 and a number of upcoming PC games for smaller discounts. Enjoy the savings.