Pretty cool!

1) It would be good if you gave some instructions about what to do. something like 'click anywhere to map out a new route'.

2) It would be enhanced if you did some geo-location to automatically figure out what city I live in.

3) It would be cool if you could convert the 'miles' counter to kilometers just by toggling a radio button or something.

But this is a great tool and I'll be sure to use it. The elevation graph was particularly interesting.