I use the numeric keypad on occasion for entering numbers. To be perfectly honest, the majority of the time I use the numeric keypad is for games (first person shooters). I use my left hand on the keypad and my right hand for the mouse.

Speaking of mice, I do like the magic mouse for most things. Scrolling is better on that than a scroll wheel on other mice for example. However, Apple took a step backwards with regard to buttons. It's useless for most games for example.