This stuff sounds interesting.  Please see also Virtual Ring Routing by Matthew
Caesar:

http://citeseer.ist.psu.edu/caesar06virtual.html

I'm not sure about the scalability/performance of VRR yet, but it appears to be
a simple hack which achieves decentralized global routability over arbitrary
underlay topologies.

The presentation typically talks about wireless link layer operation and all
sorts of bending over backwards to accomodate BGP tradition and so on, but the
theoretical essence is interesting in its own right.

Regards,

Zooko