I have a second video card installed in a PCI slot (ATI's All-in-Wonder RAGE 12. I have a dual boot system with Windows XP and a Knoppix install of LINUX, running KDE as my default desktop environment.

In windows I have my desktop extended onto a second monitor. Can anyone tell me how to pull this off in KDE (and maybe some other environments)?

Keep in mind that although I'm very familiar with Windows/DOS/PCs, I'm still very much a newbie in Linux.