Dust is your PC's enemy, but typical canned-air cleaning products create an electrically charged stream of air that actually attracts more dust. The Kinetronics Anti-Static Canned Air Ionizer (CAI) is a pistol-grip device that pops onto most canned-air brands and adds ions to the air stream, which neutralize the charge for more effective cleaning. The grip has a built-in light that tells you when it's working. For heavy-duty needs, the Pro version comes with a 12-foot grounding cord. The standard version of CAI works well for keyboards, printers, and monitors, as well as for cleaning photos before you scan them.