A good example of why it pays to be careful when comparison shopping is the Kensington SlimBlade Bluetooth Presenter Mouse ($49.99 list). This notebook mouse switches between ordinary mouse work and a mode for controlling PowerPoint 2003 or higher or other presentations at a distance of up to 30 feet from the presenting PC. If that brings to mind a combination mouse and laser pointer complete with PC audio controls, you may be thinking of a different Kensington model—the $79.99 SlimBlade Presenter Media Mouse. The Bluetooth Presenter Mouse is much more stripped down—basically, it's a mouse whose left and right buttons can double as PgUp and PgDn keys to navigate, say, a slide show.

Double-clicking a mode button to the user's side of the scroll wheel toggles between the normal and presentation configurations; as the switch is made, blinking lights illuminate the left and right arrows etched into the main buttons. The two buttons and scroll wheel are the only inputs that work in presentation mode, which disables the horizontal-scroll tilt wheel—and the mouse pointer itself, so you can't use the cursor to point at or circle an item in a slide.

Resembling a bar of hotel soap—a 2.3-by-3.8-inch rectangle with a comfortable curved top—the Win XP/Vista-compatible SlimBlade connects easily with your Bluetooth-equipped notebook (there's no adapter or dongle included for PCs without Bluetooth). No software driver is required; you can download a 7MB driver from Kensington's site, but that merely lets you adjust horizontal and vertical scrolling speed rather than reassign button functions or macros.

Once I had spent a few minutes adapting to its nearly flat-handed, ultrathin profile, the 2.9-ounce mouse proved comfortable to maneuver. My test unit was hampered by a balky scroll wheel; it took some practice to learn how to press firmly enough to scroll without pressing hard enough to click the wheel and enter auto-scroll mode. Kensington says the device's two AAA batteries should last for three months of operation.

Overall, the Kensington SlimBlade Bluetooth Presenter Mouse is a passable presentation partner, but serious PowerPoint jockeys will probably prefer Kensington's (or another company's) full-fledged mouse/pointer combo.

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