I was a Best Buy today looking for the very same thing, a GPSr that can do auto and geocaching navigation.. To my surprise, one unit said on the price card GEOCACHING READY. Ii was shocked. Check out the Garmin Nuvi 500 or Nuvi 550. What I've researched so far is that the only difference in the two is the 500 has a base map of the lower 48 United States and topographical map, the 550 has Alaska, Hawaii, Puerto Rico, Canada and Mexico, but no topographical map.
Both units allow you not only to download detailed cache info such as hints and logs, but also allow you to make field notes (i.e. found it, didn't find it, needs repair, etc) and upload that info directly to the geocaching website! I'm impressed! Now if it will only go on sale... LOL
http://www.bestbuy.com/site/olspage.jsp?sk...d=1210378664243
REI has them on sale this weekend for $290