Missing Saddle:

Integrated Pligg (open source social networking CMS) into a landing page using RSS 2.0. Visitors submitted and voted on news articles using a Pligg-powered page which then promoted selected articles to a non-Pligg landing page according to a customizable threshold.

NOTE: The site is transitioning into another, more comprehensive social networking platform and no longer uses the unique solution I created years ago at the advent of the social networking explosion.