The Asus EEE PC line of netbooks gives good usability at a small size and good price. Comes in white, black and pink depending on model. Features the Asus 1005 HA which has the highest battery life (so they claim) that I've ever heard marketed.
Screen Size: 8.9-10.1 inches
Battery Life: 5-10.5 hours
Price Rage: $349-$399
