[icegreentea]

That's the great part. You have the source code, just change the value of 'freq'!. The piezo should be able to hit high enough frequencies.

[dawsdesign]

I was wondering about that. I think I'll try it. You just have to change the second number in the playTone(1000, 500); call.

[PonyGumbo]

That's what I was wondering - I think I'm going to try this out.