iPhone app using Bluetooth

[dhanasekaran.v]

I am planning to develop a iPhone app, which need to get data from a Bluetooth device (yes the data transfer is through Bluetooth). Should be listening on Bluetooth port all the time even that app is closed(as background service, like iPod app music player). This app should also have the UI to get few more inputs from user.
Also, is what is the best way of consuming the Web Services using ObjC in iPhone app.

Kindly provide the best way to design this app.

Thanks in advance,
Dhanasekaran