The Hubs idea looks like it is a good one. I have a boatload of tools that I am sure would be useful to other IETF-ers but when I am at a meeting I am busy working on protocol proposals the tools were written to support. Meeting up on a local basis is probably a better idea. In addition to geographic affinity groups, there might be a utility to other community groups. In particular academics. Every year, people who are teaching courses are looking for interesting project proposals for their students. This is often the thing I am asked about at MIT. The project I am working on right now is designed to allow us to start making use of some of the more interesting public key cryptography beyond simple encryption and signature. It also provides a way to start experimenting with new trust models. There is a lot of scope for student projects at every level.