At first it seemed easy to me but in fact it took some time to get it work (here). So maybe these few line will save you some time 
1. Go to http://www.anddev.org/code-snippets-for-android-f33/serial-over-bluetooth-simple-test-client-t11106.html – you’ll get very nice and simple example on Bluetooth. So get to work your Eclipse with ADT plugin (Android Development Tools). You’ll have to change MAC address and it example should “almost” work. Why “almost”? The odds are that line 94 won’t work:
btSocket = device.createRfcommSocketToServiceRecord(MY_UUID);
2. Remedy you’ll find here – http://stackoverflow.com/q/4724496
This answer is real lifesaver and clue to communicate via Bluetooth from Android higher then 2.1. Many thanks to the author – Michael. He wrote the following:
“The createRFcommSocketToServiceRecord method is not working in Android 2.1/2.2. There is a workaround to call a non-public method to create the socket:
BluetoothDevice hxm = BluetoothAdapter.getDefaultAdapter().getRemoteDevice(device.getAddress());
Method m;
m = hxm.getClass().getMethod(“createRfcommSocket”, new Class[]{int.class});
socket = (BluetoothSocket)m.invoke(hxm, Integer.valueOf(1));“
I work with Android 2.3 but comments to this solutions suggest that this issue is still present in Andorid 3. It’s hard to guess whether in Ice Cream Sandwich workaround is still needed.
3. You’ll get handler to write to serial device:
outStream = btSocket.getOutputStream();
You’ll may use it to control servos from your mobile phone. I’ll write about it some other time.