I believe we all know that we can use Spotlight to do quick calculation, where we can do quick addition, substraction, and other simple mathematical operations right from within of the Spotlight window.
In Leopard, you can just type in pow(a,b) to find the value of a^b (e.g. 3^4 = 81). However, you can do it even faster with Snow Leopard by just typing a^b.
Note that you can always use key combination Cmd-Space to call up Spotlight box.