The Only Windows XP Feature I Missed
One of the only features of Windows XP that I have been missing is the 'Show Desktop' button in the quick launch bar. That little button immediately clears your workspace and tosses windows in the task bar. Sure OS X has Exposé, but sometimes it just doesn't do the trick. F11 is nice, but the windows are still there once you toggle it back on. And hitting Apple+M or Apple +H really fast isn't efficient.
Luckily I found a 'Show Desktop' clone, ironically named Show Desktop :) This little app resides either in your Dock or Menu Bar. When clicked, all of your open programs get hidden (so you can still Apple+Tab through them) and finder windows get minimized. This is as close to the Windows XP version as it could get. Now if only I could figure out how to set a keystroke to Show Desktop I'd be set!