The Earthmate is fine, but it is designed as a "black box" sensor that can only be used with another device, typically a laptop and some type of software, such as the Street Atlas 2004 product shown in the ad. (In this case, with a USB connection, that's about the only thing you could use it for.) That means changing any settings, evaluating correct operation, or using it for any other purpose is pretty much impossible.

For a few dollars more, you can get something like this Garmin Geko 201 for about USD$119. I would be inclined to go with something like this unit before the first one. The unit is very small, as is the screen, but it is a very competent unit.

As for software, there are only two typical solutions. (The MS-MapPoint is available, but is quite a bit more expensive.) The two inexpensive products are DeLorme Street Atlas and MS-Streets & Trips. Each has their strengths and weeknesses. But both share a common weekness -- each successive version is a lesser product than the previous release. It's gotten to the point where I consider the current DeLorme offerings to be utter crap, and recent MS-S&T to be almost as bad.

It seems to be generally agreed that MS-S&T 2001 is the best of all versions so far, though I'm happy (sort of) with the 2002 version. Avoid 2003 at all costs. And don't waste your time on 2004.

For Street Atlas, I've remained with SA5 (circa 1997) even though I've purchased V7, V8, "Road Warrior" edition, and a never-ending stream of garbage products. If you can get both MS-S&T 2001 and SA5 you'll probably have the best of each world. (And you can probably get both on eBay for a couple of dollars each.)

More detailed reviews to come shortly, both of GPS uses and mapping software.