TVs and projectors
If you're lucky enough to work in advertising, TV, or video production, you'll often need to screen videos at home. Whether they're commercials, shows, or just clips, you'll need a TV and a player to watch them. While a $99 13-inch set and a $40 DVD player may suffice, it'll be much easier on your eyes and ears with a plasma TV or rear-projection set. And, if audio is important, don't forget to add a surround-sound speaker system.

By the same token, if you spend a good deal of your work life giving presentations, a portable projector gives you longer reach and sharper graphics when you're in front of a big audience. In essence, a 3-pound projector lets you pitch to a large group, then pack it all up and be on your way.

Either way, you can deduct at least part of the cost of these expensive home-theater components, and you'll have the best gear there is when your World Series party rolls around. Just add popcorn.