"Let's brainstorm more about how we can help participants stay connected with each other after the event?
What about having different sign up lists, like "please include me on a group email in 3 months to discuss topic xyz", and I can start that email asking for new ideas?
OR unconference sessions owners that feel like they have unfinished business can make a list of names and request to schedule follow up hangouts or IRC meetings which I can schedule for the participants.
Let's make a "session request" template which we give to each session owner and they can make any request to the event organizers as to how we can help further their agendas in the future.
It will include options for the things I listed above, as well as a sign up sheet for names of participants who should be involved, as well as a "fill in the blank" dream section" which will be a place where they can ask for something crazy and we can figure out how we can help."