Houstondan,

If you are a PDA user, ControlVision or PocketFMS is probably the most
interesting option.

If you like Lowrance, have a look at the Airmaps.

Generally, if the airplanes you fly have a good panel-mount GPS and you
want the handheld as back-up only, I would go with a small greyscale
unit like the Airmap 500.

--
Thomas Borchert (EDDH)