After having introduced Bluetooth 4.0 chips in the recently updated MacBook Air and Mac Minis, it appears that Apple has now included Bluetooth 4.0 support in the iPhone 4S as well.
Bluetooth 4.0 allows for a new standard called Bluetooth Low Energy which is expected to allow for new kinds of bluetooth-connected devices, and also offers much greater range than prior versions of Bluetooth, with a range of up to 50 meters.
The new Bluetooth 4.0 could enable such new applications as electronic leash solutions, proximity-based uses (such as wireless locking or unlocking of doors), and range-based alerts. It’s also possible for Bluetooth 4.0 to be used as a method for contact-based payment, similar to NFC.