Little self promotion...but also very relevant for those who want GPS for a good price.
I did a review for the Spectec 2-in-1 GPS device, which works exceptionally well with the WM Treo line, since we have a top-loading SD slot.
Read here and feel free to comment here at ppcgeeks with your experience...
Review: Spectec 2-in-1 with Micro SD Memory Slot (SDG-812)