The boards given away at WinHEC and PDC for Windows 7 sensor development are now available for sale from Freescale:

http://www.freescale.com/webapp/sps/site/prod_summary.jsp?code=JMBADGE&tab=Buy_Parametric_Tab&fromSearch=false

These are a great way to experiment with the new sensors such as light, gyroscope, and accelerometer.   The price is pretty fair, and it's a nice compact board.   Even better, the Windows API Code Pack support it nicely in managed code.

Have fun!