Near enough (pt 2)...

Nearfield Communications Forum (NCF) is a complimentary technology to Bluetooth and WiFi.

The complimentary aspect of the work in the NFC Forum is its beauty. By merely bringing the devices into proximity, a BT or WiFi link can be immediately established. This allows for further higher-speed transfer beyond the initial "swipe".

I like the idea of a "bulletin board" application. This could be envisaged as an interactive pod/wall - or anything frankly - that users walk up to and touch with their phones. Any application could communicate through this proximity exchange. Messages could be swapped of the type "Paul woz 'ere", or something more "sophisticated", using any media.

I found this blog about NFC. It hasn't been updated for a while, but has lots of useful background-information posts.