Daily Mile is a cool little social site for all sorts of workouts. You can sync with Nike+ which is a plus, but no 'visual' view of your run. Manual inputs of workouts/runs can be done as well. This can also be synced with Facebook which is pretty cool. You can also 'share' challenges via email, weblink, Facebook, twitter, etc. Much easier than Nike+ for that. Viewing the challenges is a little easier too. The challenges are a LITTLE buggy from what I've seen so far. Joined a couple challenges where past runs for that month didn't show up. Kind of a downer for that.