Thanks again to all for your input!
FWIW I think I am still preferring flash memory, and my wife reports what seems to be a good deal for the SanDisk 4GB one for $150. You all make some good points to consider about connectivity, battery charging, car adapters, etc. I need to get to a store to see how I like the feel/interface of some of the different models now. I may change my tune about the flash if I understand the magnitude of the negatives for using a hard disk product when reasonably active.