Logitech Anywhere Mouse MX

Not to be outdone by Microsoft and its BlueTrack laser tracking technology, Logitech recently introduced the Anywhere Mouse MX with Logitech's new Darkfield laser sensor. Darkfield tracks on almost all surfaces, including nonmirrored glass--a surface where even Microsoft's BlueTrack doesn't work. The mouse also uses the company's new Unifying technology that lets you connect up to six Unifying-compatible keyboards and mice to the same USB transceiver. Both innovations boost the functionality of the Anywhere Mouse MX, but we can't recommend an $80 mobile accessory, especially when Microsoft's $40 Wireless Mobile Mouse 4000 works just as well on almost every other surface.

The Logitech Anywhere Mouse MX is meant to be the travel-size companion to the new Logitech Performance Mouse MX, but with a few key differences. First, the device is smaller and easier to fit into a laptop bag. Second, unlike the sculpted shape of the Performance MX, this device is perfectly symmetrical to accommodate both left- and right-handed users, although we suspect that lefties might stumble over the two thumb buttons on the left side. Still, the mouse is very comfortable to use; the shape easily conforms to your hand and the surface is covered with a thin, lightly textured coating that makes it easy to grip and move around.

The scroll wheel sits between the two main buttons and moves from side to side as well as up and down. Pressing the scroll dial itself changes it between ratcheted and smooth scrolling. The button directly below the wheel is preset to activate the new Windows Vista Flip 3D overlay where you can quickly view all of your open windows in a digitally organized stack. As with most mice, you can reassign all the buttons with the included SetPoint 4.8 software.

On the bottom of the mouse, you'll find the Darkfield laser tracking unit and a power switch to preserve battery life when it's not in use. After testing the unit on a variety of surfaces including mirrored glass, carpet, a pair of rigid denim jeans, and other irregular areas, we're happy to report that Darkfield really delivers on its promise to work on almost anything with no obvious degradation in accuracy or speed during Web browsing.