I've also been using a Garmin eTrex Vista HCx for several years. I got it for geocaching, then started hiking and used it for that, then when I started biking I bought a handlebar mount so as to use it on my mountain bike. I installed the OpenCycling map for my area in it, so I now get most of the biking trails shown. I record my bike trips and then put them into a computer program to look at and store the data. I also load in road maps once in a while.
The Vista is waterproof by the IPX7 standard. You could always attach a float or something to the lanyard, I guess. It's an excellent GPSr for the money, IMHO. It's proven itself invaluable several times when I've gotten disoriented out in the boonies. And the LCD display is phenomenal... it can be read in bright direct sunlight as well as darkness. The only drawback is the gasket around the edge needs to be cleaned and re-glued every couple of years.
I aso use a Garmin car unit, and an iPod touch with GPS and 3G add-ons. The iPod touch is nice, because I generally ride solo, and I can set it to send my location at intervals on a map to my Facebook and Twitter accounts (as well as email to friends).
GPS is not a cure-all. It needs to be used with some awareness of the limitations of the technology and, more importantly, the accuracy of the maps being used. But I wouldn't leave home without it. And plenty of spare batteries.
Last edited by jmiked; 11-02-11 at 08:53 AM.
Reason: tamned dypos