Most Smartphone/PDAs have software capable of playing at Master strength these days. Certainly a portable option you should look into.
On WinMobile, I'm running PocketShredder as well as PocketGrandMaster. For a hefty fee, you can even get PocketFritz!
I got my first tabletop chess computer for Christmas of '96. Since then, I've mastered it: two summers ago, I played 50 games on the highest level and won all of them. Its estimated rating is only about 1750, so I've been trying to find a good upgrade. Any recommendations?
I already have an excellent software program for my PC, so I'm not looking for anything like that. I want a portable (probably tabletop) model that can further benefit my chess skill for several years. I actually bought one a while back: the Saitek Mephisto Master, but its program had a serious flaw and I had to return it. What would you all recommend?