I'd agree with Maziar, the 9600 GSO is really just an 8800 GS which isn't really powerful enough to play games such as Just Cause 2 and say Crysis 2 @ 1440 x 900. You might get away with 1280 x 768 though.
Actually the card this person is talking about is not the same as an 8800GS. The initial 9600GSO was but after a while Nvidia changed the design of the card(kept the name the same. sweet irony.) The 48 shader/512mb version of the card is actually a gimped 9600GT that is a lil weaker than the other version of the 9600GSO.
That said it should still do alright for 1440x900 especially if you overclock it. It wont be able to max out settings on most current games but it will do decently when AA is turned off and a few settings dialed down.
If you don't own this card but are thinking about purchasing it then there are surely better options.