Because of its advanced features, Logitech's V500 Cordless Notebook Mouse is arguably the Porsche of notebook mice. It's also a convertible: you slide a button on the bottom of the mouse to expand the chassis 7 degrees and reveal a little slot that houses a thumb drive-style USB minireceiver. This expansion gives you a much more substantial-feeling input device than most portable mice. Two AAA batteries power the mouse, which also ships with a small canvas protective carrying case.
Aside from the convertible design, two other features distinguish the $70 (as of November 2004) V500 Cordless Notebook Mouse. The first is its solid-state scroll panel. Incorporating the same Synaptics touch-sensitive technology found in your iPod or laptop touch pad, the panel allows you to scroll both vertically and horizontally through documents, spreadsheets, Web pages, and photos by simply sliding your finger along the panel. Moving from a scrollwheel to a touch "wheel" takes a little getting used to, but with practice, you'll be scrolling smoothly in a fairly short time.
The second notable feature has to do with performance. Logitech has equipped the V500 Cordless Notebook Mouse with its new all-terrain optical engine, a 1,000dpi-resolution optical sensor matched or bested by only two other mice we've looked at to date, both gaming mice from Razer. We weren't able to tell a huge difference between this increased sensitivity and that of mice with 800dpi optical sensors (such as the Logitech MX510 Performance Mouse), but we found that the V500 worked well on a variety of surfaces, including a metal countertop, living up to its all-terrain billing. You can roam up to 30 feet away from the receiver, which transmits in the 2.4GHz range (we did not experience any interference from cordless phones).
Notebook mice, because of their small size, generally aren't terribly comfortable to use over long periods of time. And while the expanding chassis puts the V500 Cordless Notebook Mouse at a better angle and gives it a sturdier heft than most portable mice, we can't say that it's a study in ergonomics--you'll probably end up taking your hand off every few minutes to keep it from cramping. That said, the Logitech V500 Cordless Notebook Mouse is one of the more comfortable portable mice we've used. It will work fine for a few days on the road, although we'd by no means want to use it as a full-time replacement for our everyday point-and-clicker.