KeyBound

Ultrafast on-the-fly key binding for your action bars.

Type /kb to enter binding mode. Simply mouse over your action bars (works with your primary bar and multi bars) and press the key combination you'd like to use for that button. This add-on is intended for use with the stock Blizzard frames, if you use any actionbar addons this might not work and probably isn't needed. The same functionality already is provided by addons like Dominos, etc.