It would be really cool if I could minimize my WinXP Parallels VM to the OSX dock and have a hotkey to switch between fullscreen WinXP and fullscreen MacOS. I run WinXP in the same resolution as my Mac desktop- so when the WinXP window isn't fullscreen, it's pretty useless (I can't see the taskbar or start button because they won't fit on screen). Currently, I have to hit F9, click on the Parallels window (or restore it from the dock), then hit the fullscreen hotkey. It would be ideal if all I had to do was hit a single keystroke. 
-Zak
-Zak