Proof that n^0 = 1

I accept that this is so, I've had to in order to get through mathematics classes for all these years.  But I simply accepted it as fact and moved on, without ever really seeing the logic behind it.  This as been bothering me for many years.

So please post a proof showing that for any number n ≠ 0, n^0 = 1

http://planetmath.org/?op=getobj&from=objects&id=3948

Alternate: 1 = (a^n)/(a^n) = a^(n-n) = a^0.