I bought this one (Asus Eee PC 1000HA 160G - fine Ebony (XP operating system) after Greg recommended it earlier in the year. It has excellent battery life, works fast and is EXTREMELY portable. Here's a link for a website:

http://www.buydig.com/shop/product.aspx?sku=AS1000HABLK001X

It is also very reasonably priced.

Rich