I think you should hold out for the Legend! A virtual necessity with GeoCaching is the PC interface cable so you can upload cache coordinates (waypoints) to the GPS. The Legend has one, the Summit doesn't. I also find the basemapping that comes with the Legend very handy when you're looking for a cache in some unexplored part of the country. Remember, having a GPS (and knowing where you are) is only half the battle - you still need a map to know how to get there (unless you want to feel like one of the early explorers).
Down the road you may decide to pick up the MapSource CD from Garmin and then you get very detailed mapping and GIS type information. Once you've found the cache and it's time for lunch, you can ask it to show you the nearest restaurants - by cuisine if you like. It'll give you the phone number so you can make a reservation, tell you where it is and how to get there (yes, even in Manitoba)
I find the little joystick that comes with the Legend quite useful for working through the menus. If you think you need a compass as well, the built in electronic compass (with the Summit, not the Legend) is cool. A GPS isn't a compass, it only tells you which way North is when you're moving.
I think if I was buying a GPS for GeoCaching today, I'd probably go for the Vista. It's got more memory for basemaps (I find 8 MB isn't enough for a trip to Saskatoon) and it comes with the electronic compass as well. Now you're talking $280 though.
A couple of good web sites:
You're in for a world of fun!
-- Edited by TurdleEggs at 16:23, 2005-12-28