Computers are kind of like siblings. Sure, we love them. But sometimes they get really annoying. Like when all those tiny parts start whirring and purring--amplified by the popular new, lightweight aluminum cases. Luckily, a cottage industry has sprung up to help hush your PC (see silentpcreview.com for details). If your tower sits on the floor, the first step is easy: just put a small piece of carpet underneath to limit the drum effect. Things get more invasive from there. The $89.95 AcoustiPack from quietpc.com provides adhesive-backed, soundproof foam you can easily attach to the inside walls of the case. (Just steer clear of moving parts and don't cover ventilation holes.) Or invest in a new hard drive with quieter, fluid dynamic bearings, like the Seagate Barracuda V ($109 for 60GB; siliconacoustics.com). If you're handy with tools, endpcnoise.com sells quieter power supplies (like the $109.95 Nexus NX4000) and processor-cooling fans. If you're too skittish for open-PC surgery, ask the local computer store to install it for you. Or there's always the simplest option. Just turn your computer off.