Magellan currently has a very good deal going on with their "eXplorist" models 210 and its bigger brother, the 400. Rebates are $30 for the 210 and $50 for the 400.
But wait! There's more!
You can buy just the GPSr (GPS receiver), or, for not much more, buy the "Wilderness Bundle," which includes some quite nice 3D map software, a case, cables, and, for the 400, additional memory (the 210 does not accept additional memory).
Speaking about memory, many of the GPSrs up until recently had only about 8MB of memory, and this allowed one to get by fairly well. The 210 has 32MB, 22 of which is available for the user to load detailed maps, etc. The 400 accepts SD cards, and some users report they have installed 2GB!
I could pitch these a lot more, but do some web searching. Check around for best prices. Also, before deciding to buy accessories from the vendor selling the GPSr, shop around for better prices on cables, memory, batteries, whatever.
Batteries: The 210 takes two AA cells; the 400 has a proprietary Li-Ion battery.
I have a 400 and the lady of the house has a 210. We both are pleased and we do love the geocaching experience! I truly wish I hadn't held off so long before getting started.
Finally, caveat emptor, and "one man's meat is another man's poison."
Geocaching has a very serious downside: less time to climb.
Peace.
Jim