 You don't need to be an 'investor' to invest in Singletrack: 6 days left: 95% of target - Find out more
I just came across this today and thought it was pretty bloody interesting, mainly in seeing where I got dropped in my most recent road race 😳
Obviously it's really only any fun for group rides but it's interesting seeing random people come and go on the same route.
Check it out - http://labs.strava.com/flyby/viewer/#178195956
If you use Veloviewer the 'flyby' is a linked option for all your activities. Flyby is very useful for 'almost bumping into people' - you can see who it was you almost bumped into, see where they went (useful for finding new trails) and you can get in touch with them via their Strava ride... you just need to be careful not to come across as a 'stalker' 😀