PSP add-on GPS System OR separate handheld GPS Unit ?

[ruthandsam]

Please would you advise? My son has taken up the hobby of Geocaching and is in need of a hand held GPS system. He has a Playstation Portable and I believe you can by an add-on GPS system. My question is: would the add on GPS be better than a separate hand held system (made by eg, Garmin?). I'm going cross-eyed looking at reviews on the internet. The prices are similar.

[stoofur]

On the Gadget Show this week they reviewed the PSP GPS. It was ok although it only works on the older PSP not the new one. It got 3 "G" ratings. Maybe you can watch the program on the Gadget Show website?
I think that a stand alone GPS receiver is better than the PSP though. You will have a touch screen and it is a more neat package. I personally like the Tom Tom GPS.