An idea I had published on the Global Ideas Bank some years ago:
Drive-hire scheme for parking
seems to be taking off in a big way in London and the UK:
Keep the house, how much for the drive?
Interesting to see how the voting on the GIB rates the idea at "5 % feasibility". Somebody obviously thought otherwise!
Park let: The Marketplace for Parking Spaces & Garages for rent
I would not be at all surprised if the next innovation is a double-decker arrangement, where a driveway's capacity is doubled by some kind of stacking device that lifts one car above another. Don't forget where you read it first ;)