It doesn't look like city-wide pneumatic tubes are coming anytime soon, so here's an inferior alternative.

Use either overhead power lines or overhead phone lines as the infrastructure for little motorised vehicles that deliver mail, snacks, or anything else small and light. They'd hang from wheels, and be programmed by the line owners to avoid multiple vehicles on a line that couldn't take it, and maybe avoid some lines altogether.
-- caspian, Jan 06 2005

Pneumatic thingumy physical_20internet
[caspian, Jan 06 2005]

I think automated radio controlled planes (with GPS, anti-collision software etc) would be more feasible... but I still like the image of little trolleys trundling over the power lines (+)
-- xaviergisz, Jan 06 2005



halfbakery