As some may have come to recognize from some of my posts here, I use google earth for a lot of mapping applications.
I just got me a cool little GPS tracking receiver off e-bay (US) for a little less than USD 40.00(!) plus 1 Lb worth of shipping cost.
It's called "i-GotU" (e-bay search it).
It it's an inch by one and a half, weights nothing and has only ONE button which does it all.
It can be hooked on a laptop for life tracks asa simple receiver or be taken along on a trip and records the trip. You can set place marks by a simple impulse on the button. Then, back where ever home is to you, you can download the data and the software that comes with the device will overlay your trip on google earth or google map (only google earth works for here 'til now).
Sure, it's not the kind of gizmo which will seek to have long conversations with you about where you could, should or should go, but I've got a lot of fun and applications for it and for the price...