A while back Dieter asked for a fast way to toggle Airplane Mode on the iPhone -- a triple click of the home button, perhaps. Yesterday he and I were talking about all the new Bluetooth functionality in iPhone 3.0 and the same point came up -- right now, to turn Bluetooth on or off you have to:
Wake the iPhone, Slide to Unlock, (type a Passcode perhaps), (return Home perhaps), tap Settings, tap General, tap Bluetooth, and then toggle the ON/OFF switch.