I'm working on wiring Shindig[1] into my project - Quoddy[2] - to allow Quoddy to host OpenSocial[3] applications. I've also been spending some time going through the Programming Scala book.

1: http://shindig.apache.org

2: https://github.com/fogbeam/Quoddy

3: http://code.google.com/apis/opensocial/