iPhone Bluetooth Discoverability

Is there a way to enable and disable the iPhone's Discoverable Bluetooth mode without having to toggle BT On/Off...?

On other BT phone (like the Treo), it's entirely possible & quite easy to enable BT discoverability on the phone ONLY to establish pairing with another device. Once the devices are paired, it's usually easy (not to mention recommended for security purposes) to disable BT Discoverability on the phone because you simply do not need it anymore for the paired devices to recognize and connect to each other.

It seems the iPhone is always in Discoverable mode every time I go to:
'Settings' > 'General' > 'Bluetooth' (while Bluetooth is ON) it always says "Now Discoverable". Is this occurring simply because I am in the BT menu, and when I exit Discoverable goes to Off?

I'd be very concerned to think that once BT is enabled, the iPhone is constantly in Discoverable mode...!?!?

EM