Easiest way to get 3 or 4 monitors working on linux?

Easiest way to get 3 or 4 monitors working on linux?

I can use the nvidia drivers with my Quadro FX 1400 to drive 2 monitors, but I want to do 3 monitors, with the ability to drag windows among all of them, good expansion, etc. BTW, setting up 2 monitors is trivial. I just had to run the nvidia-settings program. But, if I use nvidia-settings to "enable" the third monitor, the machine will crash within minutes, at least with Fedora 12. The 3 monitors worked with Fedora 11, but not with 12.