connect to bluetooth *while* in call?

Maybe I'm missing it, but if I am already in a call using the handset, how can I switch to my bluetooth earpiece?  The BT device works fine, but (again unless I am missing it) only if I turn it on and connect to it before making / getting a call.  With my old phone, just turning the BT device on would then activate BT on the phone and connect automatically, even during a call.

Thx

If your instinct bluetooth is on you can turn on and "connect" your headset during a call.  If your instinct bluetooth (Main/Settings/Bluetooth) is off you cannot connect during a call.

No.
You cannot turn bluetooth on for your phone during a call. 
You can use the wired ear during a call. 
You can turn on your ear piece if your phone has bluetooth on.
If you want to know what you can do hit the home at the bottom of your phone during a call.  It will show you all of the functions that work during a call.  They are:

1.  CONTACTS
2.  CALL INFO
3.  MESSAGING
4.  NOTES
5.  CALENDAR
6.  CLOCK
7.  CALCULATOR
8.  PHONE INFO

I think it is cool that you can send a test massage while on a call.

I have my BT set to visible for 3 mins or something like that. I think that setting allows for your paired devices to find you and not others around you. I may be wrong, but I'm sure someone can confirm this. Anyhoo, I don't keep my headset on all the time. If I get a call and I turn my headset on, then it will connect with my phone and the minute it connects my call is switched from the handset to the headset (BT). Try leaving your phone on that setting and see if that works. Everytime I turn my headset on it automatically connects. So, maybe there is something wrong with your headset if it doesn't connect while your phone's BT is on.

I use the Motorola H700 earpiece, and I can turn on my earpiece in the middle of a call and it automatically connects during the call.  I don't have to do anything but open the mic boom and it connects.