They only make the Forerunner in the 205/305/405 configurations, and not the Foretrex. The Forerunner series does not the "Navigation Page" that the Foretrex series has. I would assume that would be useful for geocaching. Chalk one up to Garmin's marketing department, as that would be an easy bit of software to enable on the Forerunners...
--Bill
Thanks all. Guess I still have a litttle more homework to do.