Amarino Evaluation Shield
With this kit, you can send custom messages on LCD, control RGB (red, green, blue) LED, display light and temperature sensors response on the phone interface and display sms on LCD. In short, you can do several experiments related to Bluetooth and try all the Android applications made for Android- Arduino communication. The kit is just an extension of Amarino shield by buildcircuit.com.
Though the layout shows BlueSMiRF module from Sparkfun, you can do this experiment with any other Bluetooth adapter.