There haven't been many products built for Bluetooth 4.0 yet, but there are a variety of possibilities:
- Find Me - electronic leash applications
- Proximity - wireless locking and unlocking, out of range alerts
- Sports / Running - stats and vitals
- Health - heart rate monitor, blood pressure, glucose monitors
Apple joined the Bluetooth board of directors in June and Bluetooth claims virtually all new smartphones will include Bluetooth 4.0 support by the end of 2012.