My coworker sold me his WinTec WBT200 bluetooth gps device. Why, you ask? It is TINY, lives 8 hours on it's rechargeable battery, and you can set it up to record your location at set interval (like every 5 minutes or so), and then download the logs. Then there is a program that will look at the exif times in the pictures you have taken, and then insert the lat/long data from the nearest time stamp in your gps log.
As a bonus, it works with google maps on my blackberry.
It also comes with a utility to overlay your paths on google maps.
Finally... There is a mapping software I can buy for the blackberry that works with the gps and it has topo maps that are good for hiking.