In a recent post, I linked a video that outlined my initial experiences with building XAML applications for the Sitecore desktop. Coming off that experience, I was super excited to try out another application--SocialMe is the result.
Basically, SocialMe allows Sitecore users to save social networking credentials (currently Flickr, Twitter, and Facebook) to their Sitecore user profile, which can be leveraged on a web site to display custom content for that particular user--recent tweets, uploaded photos, and most recent Facebook status.
Anyway, here is an overly-long video that describes this in fuller detail, as well as provides a demo of what it allows you to do.