I'd like to start using GPS to track my workout, but all I really need is a small device that I can stick in my pocket that will track my position. I did a google search and all I seem to be able to find is $400 Garmin mini-computers that do everything but ride the bike for you.
It has no reviews, though, and truth be told, I could do without the MP3 player part. Does anyone know of a decent (and cheap) device that *only* logs your GPS position every second and *nothing else*?
You could always consider a Garmin 305 as well... I have one that I use for my main road bike (with a speed cadence sensor - If you were only interested in the GPS aspect, you would not need that though). They are about $125-$130 from Amazon. Garmin connect online software is really nice and gives a lot of very useful information. (including GPS info - directly transportable to google earth)
When riding my mountain bike - I just use runkeeper on my smartphone though. (just to keep my fun rides and training rides separate)...
You won't be sorry with the garmin 305 Forerunner. I used one for years and it trouble free, easy to use and up loadable to garmin connect or other web sites so you can track your info. Its worn on the wrist like a watch or on the bike too. Just a warning about the bike mount, you can't trust it to stay on the bike, but its easy to fix. Goolgle it Good luck.