I saw the new Go! Motion in action today at the Ohio Section of the American Association of Physics Teachers meeting, and it looks slick.
The setup is easy (plug into the USB), the cost is low ($ 99.00, no additional parts needed), and the software is Logger Lite (shown displaying the Go! Temp data below.
Another great science toy presented today was the World Wind software. In the words of the NASA site
World Wind lets you zoom from satellite altitude into any place on Earth. Leveraging Landsat satellite imagery and Shuttle Radar Topography Mission data, World Wind lets you experience Earth terrain in visually rich 3D, just as if you were really there. I've placed a sample screen shot below.