Well, after much searching, it came down to:
Transcend Digital Album - about $300 for a 20GB device that has a color LCD & TV out. Also reads multiple memory card formats.
Smartdisk Flashtrax - $250 after rebate for similar gadget as above, but CF only.
Archos GMini 400 - MP3/video/photo gadget with 20GB storage - a little more expensive.
Portable HDD with no LCD or TV out.
I'm sure I'd make use of the TV out capability for slide shows. I'm also sure that such devices are only going to get better & cheaper & more plentiful ... the best of the bunch are the Jobo & Epson units for around $500. I may also look at ones that read
from a memory card, rather than relying on a HDD.
I ended up ordering the Wolverine 40GB HDD with verify function direct from Wolverine for $199 (same price as B&H who has it on backorder & Wolverine has free shipping). Battery life is rated at 6GB of transfer (presumably with slow cards) but if I can dump my 2GB worth of cards to it once on battery I'll be happy - chances are I'll only use it in a hotel room on A/C power anyway - then I don't have to worry about battery power if I run a verify before formatting the card. This gadget also reads 7 card formats, handy since we also have a Sony that uses Memory Stick and I'd like to eventually get another pocketable digicam that may use SD or something else.
So thanks everyone for your advice !