Are you interested in or currently building out applications that use claims-based identity? Come join others who are also working on similar systems and discuss your successes and pain points with federated identity. I'd love to hear about your experiences interoperating with other systems, using Windows Identity Foundation (formerly code named Geneva Framework) and other frameworks, and so on. Are you using information cards? What do you think of the new direction CardSpace is taking? I'm sure we'll have a lively discussion!