Boulder Running has created a Google Maps mashup called Google Mapper that allows you to use your mouse clicks to plot your running route. It plots your course and calculates the distance. I plotted my favorite run - the Rail Trail - 6.5 miles out-and-back (use the "satellite" or "TS-UA" view to see the trail). It appears that it only is available for the Boulder area, but Map My Run will let you do it anywhere. It's a fine tool to estimate distances if you cannot afford one of these.
[Those Polar watches may be great heart rate monitors, but their distance function does not use GPS; they use "advanced sensors" to calculate each stride. Sounds like a glorified pedometer to me - no thanks. How 'bout a real GPS running watch. I wonder if these watches can upload data to a computer to plot maps.]
