Use a Paper Clip to Power a Remote with One Battery

Easy Remote Control Battery Hack - Funny bloopers are a click away

As commenters at the Metacafe video page point out, using just one battery reduces the range of your remote, and might not work at all with some equipment that requires a certain amount of signal strength to activate. That said, connecting two terminals with an easily-bent paper clip is pretty easy electrical engineering, and it might just save your butt the next time friends are gathered to watch a DVD and your player's remote is one AA short of a full deck.

While you've got your remote open and your DIY cap on, try boosting your remote range with tinfoil, or any of the other remote hacks listed at Wise Bread on the via link.