I liked how ATITool had a built-in graphics test so you don't have to load up a game every overclock. Any tools like this for Nvidia? And while I'm at it, would memory heat sinks effect the memory OC much? They don't look like they do much, and I have a Zalman fan. And what's the temp your vid card should stay below when OCing? It was 60C right?
More aboutoverclocking program nvidia atitool
ati tool will work for nv cards.
you might also try coolbits.
Nvidia's 8800 drivers have a built in stability test, but I think you can use ATI tool on Nvidia cards for the artifact scanner, although it may run on the 2D speed and that would do you no good.