Originally Posted by GigoloShawn

Nah - but you don't want to use acidic items that produce electricity; if you use lemons it will chew the plating off of the wires.

I miss 8 year old science sometimes, some of it was awesome.

Best I ever did was use a solar cell to trip a relay connected to an incredibly obnoxious buzzer. So, you know, you could uh, know the sun was still there.