The Microsoft Explorer Mini Mouse made its debut last year alongside its big brother, the Explorer. At just $60 ($20 less than the Explorer), the Mini model retains the same BlueTrack sensor that lets you use it accurately across a variety of surfaces that a normal laser mouse just can't handle. The only big differences are the smaller footprint and the nonrechargeable AA battery that powers the mouse and its USB receiver. The mouse isn't perfect, and lefties get the cold shoulder once again, but its accuracy and convenience make the Explorer Mini Mouse one of the most ideal travel companions to have in your luggage.
The highlight of the Explorer Mini is a proprietary technology that Microsoft calls "BlueTrack." BlueTrack combines the precision of laser tracking technology with the wide coverage of a standard optical mouse to let you use it on virtually any surface. This versatility should come as a relief for jet-setters who don't want to lug around a mouse pad around with their hardware--now you can mouse on a variety of tabletops, carpets, and other rough or reflective textures. While these surfaces present a problem for traditional mice, the Explorer Mini scrolls beautifully across all of them. The one exception we found is glass. In that case, the cursor became erratic, moving very slowly at times and jumping across the page at others.
From a design perspective, the Explorer Mini is almost an exact replica of the full-size Explorer, minus approximately an inch cut off around its edges. At only 3.82 inches long and 2.74 inches wide and a svelte 0.22 pounds, the mouse fits comfortably in any laptop case or carry-on bag. The top of the mouse features the two main click buttons, and the side has two additional, vertically oriented buttons that you can program using the included software. In addition, the Explorer Mini has a smooth wheel up top for scrolling, but we still prefer the capability to switch between free-spinning and notched scrolling, as in Logitech's VX Nano Cordless Mouse. Unfortunately, we have yet to see that mechanism in a portable mouse. Also, southpaws shopping for a new mouse should turn their focus elsewhere, as this one is ergonomically shaped to fit a right hand.
A single nonrechargeable AA battery powers the mouse, and you get one in the box to start you off. The Explorer Mini's plug-and-play design also allows for incredibly easy setup with both Windows and Mac OS: just pop the USB 2.0 receiver off the bottom, plug it in, and the mouse will automatically install the drivers you need to get going. Unfortunately, the only way to turn off the mouse and save battery life is to take out the USB dongle and stick it back into the Explorer Mini itself. In other words, you can't just leave the receiver in your computer and slide a switch on the mouse to turn it off.
Updated on August 10, 2009: The overall rating was initially incorrect, due to an error. The actual rating is 8.3.