Desparkifier

One of the puzzles that vexes those who dabble in electronics is what to do with a capacitato that's holding a charge.

Some might say the best use is to throw it at a friend/enemy in the hopes that they'll touch both leads when they catch it, thus discharging it. Others will say to lick the terminals yourself to get that "tastes like a lot more than 9 volts" experience.

But eventually once the novelty of those solutions wear off, most folk build one of these out of an alligator clip test lead and a 5w 20kΩ resistor.