Wcheung built a really slick app hosted on Cloud Foundry using Grails and Pusher. If you haven't seen some of wcheung's videos before you have to take a peek. Not only are they technically awesome to watch but his delivery skills are very entertaining. Wcheung demos are legendary inside CloudSpokes!
This was a great submission by wcheung and we've already rolled his code into production and it's pumping gamification data into Badgeville on a regular basis.