DigiPro WP5540 5x4" USB Graphics Tablet w/Cordless Pen (Black)
I purchased this graphics tablet to work with my Asus EeePc about 2 weeks ago. It is pretty bare bones but works wonderfully under Windows XP. The only downside I see is that the pen requires a battery (which is included) which will eventually need replacing.
However, there are tips in the manual for extending the life of the battery, the most important of which is to never rest the pen nib down. The nib acts as a switch so when it is pressed, it draws power from the battery.
Understandably, a Wacom tablet does not have this limitation and there are low-priced Wacom tablets available. However, I am so far very happy with this purchase and works as advertised.