Has Pi got any uses not to do with circles?

You're welcome. BTW, I almost forgot their most classic pi comic.

Hats and crop circles. Ah nevermind.

Even though Pi is the ratio of a circles circumference to its diameter, it does have an amazing amount of uses unrelated to circles. First, there's Euler's Identity, the equation mentioned earlier: (e^(pi*i))=-1 (or (e^(pi*i))+1=0).

There's also Buffon's needle problem.

Even stranger:
1) Measure the length of a river, as the river flows. Call this x.
2) Measure the length of the same river, but this time as a straight line from the start of the river to the end. Call this distance y.
3) Divide x by y. Call this result z.
4) Repeat steps 1-3 with as many other rivers as you care to.
5) Calculate the mean of all the zs you calculated. The more rivers you do with this, the more closely the mean will approximate Pi.

Scott, that last fact is funnier if you pronounce pi the way everyone but we anglophones does.

John