The Kensington Ci95m Wireless Mouse with Nano Receiver definitely lives up to the nano standard it claims. Sitting less than 25 mm high, the mouse fits comfortably in the hand, and the side and back rubberized grips make it feel secure. The USB receiver is so small that it almost becomes part of the computer when plugged in. This allows you to just leave the receiver in a laptop port while traveling (or in any USB port on a desktop computer) without having to worry about damage.
Powerful magnets join the top and bottom of the Ci95m, but they can be easily pried apart. Kensington also placed a fourth magnet inside the mouse to let users store their receiver safely. As an added benefit, the removable top facilitates quick battery changes.
Users do not need to worry about inadvertently draining their mouse's AA batteries, as the Ci95m has a tab that slides over the laser, turning the mouse off. The mouse also shuts off whenever your computer goes into sleep mode. Kensington promises six months of battery life.
The Ci95m shows little innovation when it comes to its three buttons, using only the standard left- and right-click and scroll wheel. Clicking the scroll wheel reveals the Exposé features, which is nice, but not awe-inspiring. The mouse works right out of the box--no drivers are needed, and that's a good thing. But without drivers, there's no way to program the mouse for other, more customized functions. The Ci95m is available only in one rather pleasing two-tone gray and black design.
My only real criticism of Ci95m is that the laser can sometimes be tricked by certain surfaces. Some shiny surfaces, for example, may cause the mouse to get stuck, and that can be rather annoying. However, a remedy as easy as a mouse pad will generally solve this problem.
Macworld's buying advice
Kensington's Ci95m Wireless Mouse with Nano Receiver is made for travelers, and while it doesn't specifically advertise itself as an ergonomic mouse, I found its slim form quite comfortable to use and relaxing in the hand. It's great if you're looking for a mouse that is light and easy to carry around. If you crave innovative buttons that facilitate different functions on your computer, you may want to look elsewhere. But as an everyday travel mouse, the modestly priced Ci95m is a fine investment.