Sent to you by nunok via Google Reader:
NFC functionality on a smartphone has its utility, though it's few and far between. In recent I've seen a few Bluetooth devices emerge, specifically speakers such as the Beats Pill, that allow you to pair the two devices by tapping them together. It's functionality that is sure not to make an iPhone owner jealous, but in the event that it does you can now turn to the CalypsoKey, an NFC infused case specifically built for Apple's handset.
Needless to say, functionality is limited to what products are available, and to be candid I'm not sure how you, a consumer, could easily add identifying info to the tags. Nevertheless, I want the wireless key solution shown in this below video, which is supposedly from Kaba. From the looks of it you just plug the mechanism into the door's deadbolt. But I'm confident it's not that simple, especially since doors in the US generally have a deadbolt knob/switch on the inside as opposed to a key insert, as seen in Europe.
In terms of specs, Calypso says their RFID cases have one 13.56 MHz RFID, ISO 14443A antenna with 1k memory capacity and a second 125kHz RFID antenna built in. It's also compatible with most RFID NFC worldwide access points.
The CalypsoKey NFC cases comes in two types and starts at $100.