[scott_s]

A less radical approach is to use multiple screens/desktops, but all under one account. Under OSX, they're called "Spaces," and I can't remember what the Linux term is. I'm not sure if Windows has them.

[gknoy]

I used VirtuaWin for about five years in Windows, it works excellently. Not as perfect as the ones in Linux, but close.

[Evbn]

They are called "desktops" on Linux.