Wristwatch Heart Monitors

Any runners know where I can find a good distance counting watch?
I am an avid runner, I run approximately 23 miles a week. (about 4 1/2 a day) I am in the market for a wristwatch that can actually calculate the distance you’ve run per session in mile increments. Any ideas where I can find something like that? The only thing I can seem to find are heart rate monitors, which isn’t what I’m looking for.
Your best investment, especially if you care about accuracy, is likely one of the GPS units.
The Garmin Forerunner 305 probably remains the best value out there. You might look at the 205 as well.
Sporty Watch Blue with Calorie Counter Pulse Heart Rate Monitor