I occasionally cover hardware in Mac Gems, and two of my favorite such products have been portable mice: Back in September 2004, I reviewed RadTech’s BT500 Bluetooth model, and the next month I covered BenQ’s RF-based M310. If reader email is any indication, I’m not the only one who prefers a mouse to a trackpad if space allows, and both the BT-500 and M310 fulfilled my requirements for a travel-friendly pointer: small size, multiple buttons, and wireless functionality.
Both products have recently seen updates that should make them even more appealing to road warriors. The new $40 M310 Plus ( ) fixes a bizarre problem with the original M310—noted in my review —that prevented it from working with Tiger (Mac OS X 10.4). But beyond that, both the M310 and the new version of Radtech’s BT500 ( ; $60) offer a welcome improvement: the ability to easily recharge their batteries.
Like their predecessors, the M310 Plus and BT500 each runs off 2 AAAs; you can use standard alkaline batteries if you like. However, the new models each include a pair of NiMH rechargeable batteries and a cable that allows you to charge those batteries via your laptop’s USB port.
Owners of Bluetooth-equipped laptops will like the new BT500. At just over 3 inches long and just a few ounces in weight, the BT500 takes up little space in—and adds little weight to—your laptop bag. Yet it provides a two-button, 800dpi mouse with a clickable scroll wheel and a comfortable (for the size) design. Radtech estimates battery life at 75 hours via the included NiMH batteries; I used the mouse for about a week without needing to recharge. When the batteries do run out, you simply plug one end of the included cable into a USB port on your laptop and the other end into a small port on the front of the mouse; you can continue to work while the batteries charge. (The BT500’s scroll wheel includes blue, red, and green lights to indicate battery and connection status; when the light turns green, you know the mouse is fully charged.)

Although the BT 500 works as expected without drivers—as with any multi-button mouse, you can assign Exposé/Dashboard actions to the second mouse button and the scroll wheel button—Radtech also provides their own software driver, RadMouse, downloadable from the company’s Web site. With RadMouse installed, you can set custom mouse pointer speed and acceleration, as well as assign custom actions to each button and the scroll wheel. Actions include modified mouse clicks, keystrokes, keyboard shortcuts, special keys (volume, brightness, eject, and the like), scrolling, and launching applications or opening files. You can even set up different configurations for different applications, so, for example, the scroll wheel button can open a link in a new tab in Safari but close the current window in the Finder.
As I mentioned in my review of the original BT500, a minor complain I have is a consequence of a desirable feature: To preserve battery life, the BT500 enters sleep mode after a few minutes of inactivity, and it takes a few seconds to wake up when you use it again. I also found that I had to insert Radtech’s included USB/power cable firmly into the mouse to get a good connection; the mouse’s indicator lights were quite useful in this respect, as I was able to easily tell when the mouse was actually getting power.
If your laptop doesn’t have Bluetooth, or if you prefer to keep Bluetooth disabled to preserve your laptop’s battery life, BenQ’s M310 Plus is the way to go. Like its predecessor, the M310 Plus uses radio-frequency technology instead of Bluetooth, which means that it requires you to connect an RF receiver to a USB port on your laptop. But unlike most RF wireless mice, the M310’s receiver fits inside the body of the mouse for storage: Press a button on top of the mouse to pop out the receiver; when you’re ready to pack up and go, the receiver slides back in. A dongle can be a hassle with any hardware accessory, but the M310’s dongle design is about as convenient as it could be, and it means the mouse doesn’t take up any more space in your bag than the BT500—and you’re less likely to accidentally leave the receiver behind.

In fact, the M310 Plus is almost exactly the same size as the BT500—the main difference in shape is that the M310 is oval-shaped, whereas the BT500 has a more contoured design. (I actually prefer the M310’s shape for extended use, as the slightly wider front makes makes it a better fit for my fairly large hands.)
Like the BT500, the M310 Plus runs off 2 AAA batteries; although BenQ doesn’t provide battery estimates, I’m currently going on a week of off-and-on use without recharging. Given how easy it is to charge the M310, that seems plenty good enough to me. And how you charge it is almost exactly how you charge the BT500: A cable—this one a USB-to-mini-USB—plugs into your laptop and the front of the M310; the scroll wheel glows red to indicate charging. However, the BenQ offering suffers from one major drawback here: Because the M310 Plus uses a USB receiver to connect to your laptop for mousing, charging the mouse means you must either take up two USB ports—one for the receiver and one for the charging cable—or do without the mouse while it charges. (The BT500 obviously doesn’t have this restriction since it connects via Bluetooth.) It would have been useful if the M310 was able to connect to your computer via USB while charging. That said, given the M310 Plus’s long battery life, as long as you charge it when you’re at home, it should last for the duration of most trips.
Both mice include a hardware On/Off switch that lets you turn the mouse off completely to preserve battery life—important when your mouse is bouncing around in your laptop bag. On the other hand, both also come with the same caveats for use: First, as with most “travel” mice, although their small sizes are great for conserving space in your bag, those dimensions also mean that these mice aren’t the best for regular, day-to-day use (unless you have tiny hands, of course)—use them for too long and your hands will long for a full-size model. Second, although the ability to charge a wireless mouse via your laptop’s USB port is a great feature, keep in mind that doing so drains your laptop’s battery if your laptop isn’t plugged in. So it’s best to charge the mouse at home or once you’ve reached your destination—not in the middle of a transatlantic flight.
These caveats aside, the BT500 and M310 Plus are great options for the laptop user who prefers to use a mouse but wants to keep their load light.