First of all, ask yourself whether you really need one. Will you actually use it for customer demos? Are you really going to work enough on the plane to justify spending the price of a Hawaiian vacation?
Okay, okay. Let's say you do need a notebook computer. Consider the Toshiba 2100CDT: 400 MHZ-fast, with an active-matrix screen, 64MB RAM, and solid construction, all for $1,480 including shipping, from www.egghead.com. Willing to live with a small screen, a basic Microsoft CE software suite and a slightly squooshed keyboard in exchange for a 2.5-pound carrying weight, a six-hour-plus battery and an amazing price? Get the HP Jornada 820 for $618, including shipping, from www.onvia.com.