The Garmin eTrex
The Gotham Gal's mom got the kids a Garmin eTrex as a hanukkah gift. She figured they'd love the GPS/map combo for our trip to Italy. It was a great gift.
Jessica figured out how to use it and we've found it handy at times, but it could be so much better.
As it stands now, the eTrex is useful but not the killer app.