- Group purchasing for work - what if you wanted to break the cost of a Foosball table up over a group of people. It's cheap if you have enough people involved.
- App for finding which stores are open at 11pm (or on Sunday in places where most things are closed on Sunday)
- Swarm - Reverse how people get taxis, register that you're looking for a taxi and expose to taxi drivers where all the people are
- Reverse registry - wedding registries are obnoxious...register your gift so that people don't buy the same thing.
edit: formatting