I like Garmin Forerunner 305 GPS Receiver With Heart Rate Monitor quite a lot.
I've had it for about three weeks, and have used it on 12 workouts so far. I use it primarily for running, with biking a secondary usage. The main reason I wanted it was for the instantaneous readout of distance, running pace and heart rate, the latter needed for the speed work I want to do this running season.
It was easy to set up.
Inside the box you will find a Forerunner 305, Garmin Training Center CD-ROM, heart rate monitor, docking cradle, expander strap, A/C charger, USB cable, owner's manual, quick start guide.
The only disappointment is the point-in-time (instantaneous) pace measurement: It varies wildly during a run. I see swings as big as +/- 3 minutes/mile. I'm a marathoner and I know my pace is fairly consistent during a run. I just looked at my run today, and according to the data the first mile varied from 5:57/mile to 12:06 mile.
I suspect the problem is either in the averaging algorithm (too short a distance?), or in the uncertainty that results from different satellites coming in and out of view.
This is a fantastic product and the cost-benefit now is absolutely amazing. I think everything has already been said!