This is a neat idea. However, by enabling the user to post "just ran 5 miles" you are just duplicating the point of Twitter! More compelling, to me, is a site

This is a neat idea. However, by enabling the user to post "just ran 5 miles" you are just duplicating the point of Twitter! More compelling, to me, is a site that scrapes your Twitterfeed for "<action verb: ran/biked/swam> <#> <miles/km>"-type posts, and tracks the data automatically through a website. You could increase your conversion rate through a bunch of neat hacks: 1. Using a script to scrape tweets like this and DM them once you have X datapoints charted, inviting them over 2. Allowing people to view their history without registering, just by going to http://<website>/<username&#62 http://<website>/<username> -- you could spider their tweet history on the fly