Strava is a good tool for documenting rides and the data collected. It keeps track of routes and times, so if you want, you can try to improve on your time reriding the same route. Some (me), use a Garmin and link that to Strava. My Garmin will tell me if I am behind or ahead of my best time on that route and also tell me when to turn. Good stuff!

Cons would be like others have mentioned, it will make a fun event competitive if you let it. So, what's wrong with a little competition? lol