For those who missed this link or haven't heard of it, it's a good guide for controling fan speed of & overclocking the video cards. I just lowered my stock 8800GT's idle temp from 60ish to 53'c with the fan running at 45% (the sweet spot without the annoying/whining noise).
If you just want to control the fan speed, read all but the last sections.
Creating Fan Profiles
Creating Launcher Items
Configuring Automatic Fan Control
Creating Overclocking Profiles