To find a "lost" window (displays off the side of the screen after undocking from multiple monitors):
XP: Right click the icon on the taskbar, select "move", then use the arrow keys to move the window to where it is visible.
Windows 7: Hover your mouse over the icon on the task bar until the thumbnail appears, right-click the thumbnail, select "move" and then move the window with the arrow keys. Alternately, you can click the icon on the taskbar (so that the application has focus), hold down the Windows key, and press the right or left arrow key. This will snap the window to the side of the screen. (Sometimes, you have to hit Windows-arrow multiple times.)
Windows 7 has "mouse gestures". You've probably seen what happens when you drag a window to the top of your screen, but try grabbing a title bar and giving your mouse a shake. It will minimize all other windows (or bring them back if you just minimized them that way).