blogshield.com
Quick Facts:
Language used | Ruby on Rails
Written in around 3-4 hours by Jay Phillips and idea initially conceived by Cody Marx Bailey.
A web service with web frontend for managing, registering, verifying the authenticity of blog posts around the internet. The need for this was realized when content needs to be published to multiple websites legitimately. Currently, blog indexing services will penalize your site and others for having duplicated content as well as non-authorized publishers essentially "stealing" your content and reposting it as theirs.
BlogSheild provides Google, Bloglines, FireFox users, and other applications the ability to verify that a post's author has allowed it to be reposted on other sites. Plug-ins for WordPress, MovableType, Performancing, etc to interface with the API to verify, track, lookup, etc.
Each post will have a GUID (essentially a 64bit MD5 sum) that is generated from the posts content and meta-data. This GUID will be passed back to the registering party via the website (if registered by hand) or via webservices if done through a plugin in WordPress, Moveable Type, etc.