Portable DVD player. Bought it for an incredible amount of $ in about 2002. Used it on a couple of int'l flights and never used it again. Heavy, bulky and the battery needed (warranty) replacement like twice. It's gathering dust in my cabinet at home.

HP Photo Printer. Again a mid-2002 purchase. I was going to finally start printing out digital photos and make albums and such for family and friends or at least send them a recent photo. Discovered this crazy thing called oFoto. Never looked back at the thing.

A pair of those new "Free Radio" band walkie talkies. Got a little more use out of these on a multi-car road trip or two but they also seem to have fallen by the wayside.

No really a gadget per se but like Catcher in the Rye, whenever I see a power strip or multi outlet extension cord at Home Depot or Lowes, I need to buy one. When I lived in a small un-renovated apartment, I probably made Con Ed a hefty profit with all the juice I was sucking through those things (to say nothing of the fire hazard). Haven't given up the habit. ETA .... Now I have dozens of them in a huge Intercontinental Hotels cloth laundry bag in my closet.

ETA - Sony Memory Stick mp3 player. It looks like two AA batteries stacked on end. Held about 20-30 songs and worked with my old (1997-1998) Dell laptop. Still sitting around.