The BU-353 is an USB mouse GPS. It came with no mapping software although I currently use iGuidance (see other review).
This is actually my second as the first died and was replaced under warranty. The handling of the warranty was fairly quick and I have no complaints (besides that it did die).
It has been compatible with every program I've tried, DeLorme's, Microsoft's, and Navtech's, and with a port replicator can be used with multiple programs at once (I use it with both iGuidance and RoadRunner). To install it you simply instal the driver, a usb to serial emulator. It also comes with a program which you can use to test it.
Unlike my Garmin GPS III+, it gets perfect reception inside my house, and in the car, (it sits on the dash) I've never been unable to get signal - well except in tunnels.
It runs at 1 Hz, so its refresh is a bit jerky in all programs I've tried which is the only disadvantage I see to using it plus a computer as opposed to a dedicated aftermarket GPS system.