In my opinion, the best GPS unit on the market right now is the Garmin 60Cx (or 60GSx). These work well in a car and on the trail. It can do turn-by-turn routing for driving, or you can load it with topo maps for outdoor use. Color screen, waterproof, long battery life. The only down side is the price. Stree price of $450 for the Cx and $500 for the CSx (which adds a compass and barometer). Mapping software will also add $100. This "x" means that the memory comes in the form of removable memory cards. You can load this thing up with 512MB if you want.

A bit pricey, but I want one as soon as I can afford it to replace my old Meridian Platinum.

If you want something smaller, the eTrex line is nice, but you get less memory. If you want cheaper you can get the 60C or 60CS. That will save a little money, but you loose upgradable memory.

I am an owner of a Magellan Meridian. My experiences with that unit have convinced me to stay away from Magellans hand-held line. They are very slow to update firmware, and I do not like the way that their mapping software works. Somebody else mentioned the Gpsinformation.net site. Go there and click on the "what's new" page. Garmin dominates here. They are always updating firmware and introducing new products.