Mush and Paste
I've added a service to Mush that demonstrates the concept of dereferencing linked locations. Only GeoRSS entry locations are currently supported. See the wiki page there for more details.
I was going to use this as an excuse to learn more about Pylons. What I ended up learning is that I don't like Routes, the default Pylons URL dispatcher, and so I just made my own Selector-based app deployable with Paste Deploy. The public read-only repo for Mush is now here.