Haven’t tried it myself, but looks like it is worth a closer scrutiny. Am I what about talking? A route planning software for Mac/iPod!
If you want a free version of this that runs on Windows, try Google Earth. Under Tools–Measure, you can measure a specific path, in different increments (Miles, Meters, Centimeters, Yards, Nautical Miles, Smoots?). I know because I’ve been using it the past few days to figure out how far I’ve been riding.
Yesterday I rode 4.62 miles, or I should say, I pushed my unicycle through mud and clay for the majority of the distance, since Google Earth didn’t show that the path has been barely free of snow only in the last couple of days!
edit: I just noticed that they have a version for Mac as well.
Good that there is a mac version, bad that it does not cover the outback where I will be riding …