I have had very good luck with a Garmin 38 GPS receiver. It runs
about $150 at most discount outlets. It does pretty much everything you
asked about, and fits comfortably in the palm of your hand. The typical
horizontal accuracy is better than 30 meters. Vertical accuracy is not
nearly as good, but that's typical for the inexpensive GPS receivers.
I used it to guide me on a driving trip around the Republic of
Ireland last summer and never got lost once in a country notorious for its
lack of road signs. I just read latitude and longitude off a Michelin
road map for "waypoints" each night for the next day's travel, and keyed
them into the receiver. Even with the map inaccuracy, the unit almost
always pointed me in the right direction. Once or twice I did head down
the wrong road, but within a 100 ft or so it was telling me that I was
headed the wrong direction.
Hope that helps.
Mark
Dr. Mark H. Shapiro
Physics Department
California State University, Fullerton
P.O. Box 6866
Fullerton, California 92834-6866