I'd like to use my iMac's audio (i.e., microphone and speakers) for a call that is handled on my Samsung galaxy i5000 Android 2.2 phone. Is that possible?

I've paired my iMac (OSX 10.6) and smartphone through Bluetooth. Then, during a call, I opened the context menu on my phone (where you can also enable/disable the speaker of the phone), but the Bluetooth icon is disabled. (although Bluetooth itself is active and working, e.g. from my iMac I can see the files on my phone).

Is there any way to get the above working?

(I wondered whether to post this under apple- or android-stackexchange, but given the Bluetooth icon being disabled, I decided to post it here)