Connect arduino to bluetooth device

I have a Jawbone UP2. I'm looking to connect it via bluetooth to my arduino and have the arduino turn on lights, etc. when I come within bluetooth range.

Is this possible/what parts would you recommend?
How to I break into the Jawbone device?

I think it is possible, but it might be pointless. I don't think you need to break into the Jawbone device.

You would need to use a BT-4 device on Arduino, like the HM-10, configured as a master. It is likely to need to be configured to auto-connect with Jawbone but, in that event, Jawbone would need to be disconnected from the phone. This rather defeats the original purpose of Jawbone and, if you do that, you might as well use the phone anyway. It all sounds like more trouble that it's worth.

It may be possible to have HM-10 constantly sniff for Jawbone and respond, even though it cannot connect with it.