http://www.sharpusa.com/products/TypeLanding/0,1056,112,00.html
The most recent one can be found here!
http://www.mobiletechreview.com/Sharp_Zaurus_C3000.htm
The one I fancy the most!
Linux powered PDA with quite a large longevity and has a HDD, besides the obivious points for extreme rarity and high IT knowledge, it actually looks good enough to show in public… Unlike most of our current Hardware!