I bought a Navman PiN 570 (i'm in Australia) and found it to be a great unit but I cannot seem to be able to load waypoints into it for geocaching. Therefore I am going to take it back to the place of purchase and either exchange or get my money back. No where can you install waypoints to help with geocaching. I even contacted Navman themselves and they told me that they do not have software to support it but suggest I try a program called oziexplorer. Navman made it very clear that they do not support this software. I could not get it to work.
I also tried the above mentioned programs but they would not talk to the GPS in the PiN 570. Now having said all of that the unit itself is great. I recently went interstate and it worked a treat. We did manage to find some geocaches but a few of them were lucky guesses. I am sure we also missed a heap as we couldn't upload waypoints to see where they were. As a Navman it's great and as a Pocket PC it's great but for geocaching it falls down badly. I was hoping to combine both units but unfortunately I won't be able to.
I will most likely swap it for a Garmin GPSMAP60C and buy a seperate pocket pc. As my wife and kids are really keen on geocaching I have been told to get whatever we need. Not very often I get that sort of approval.