I miss my buttons (have an iphone now)...
Part of my WM reinstall is always to install hbutton from xda-devs... excellent tool to map several shortcuts to a single button.
I found i really only needed 2 at the max.. any more and I'd forget what was where.
The best (or worst) of hardkey remapping I had was when I had an old palm PDA and had remapped all 4 hardkeys to 3-4 apps each. short press, long press, double press, triple press...
Those were the days....
HButton - PocketPC Button Enhancer