I envision "the next big thing" as connecting needs with wants outside of the current economic and social structures, down to the smallest scale.
Teacher learns as much as the student.
Sue likes teaching cooking. Sally wants to learn and will bring food.
Grandma Bessy needs someone to help move a few things around the apartment and can pay $1. Joe is downstairs chilling on a stoop, could use a buck and likes helping people.
Will likes teaching programming and gets the bug for a little community hacking session. Scott and Joe and Sue and Larisa are dying to have a little mentoring and work on real cool problems, even if for a night.
Corner farmers market is nearing close and half the produce is about to be discarded. Community center has a nice kitchen and who wants fresh vegetable soup?
Connections and options that would never have occurred otherwise.
Throw in a recommendation engine and reviews of the participants.
Outsourcing on the micro scale.
Temporary autonomous zones.