Correction Palit has an over clocking tool that comes with its install CD.
Just a question.
Where did you hear Palit is a good card? I have a Palit GTS 250 and the performance versus the same MSI GTS 250 is bad so just check and make sure.
The program is called Rtuner or Riva tuner i think. I can really remember the name, coz I dont OC my card so I dont use it. You can manually set all the clocks and control the fan speed with the program.
Rivatuner does not work with the Fermi cards.