use my T610 cellphone AS a bluetooth headset for voip calls

I have been experimenting with using a bluetooth headset with skype on
my ibook. It works, but it's a hassle to set up, one more thing to
keep charged, and one more thing for my baby daughter to dissect and
eat.

Now, I can get my ibook to talk to my cellphone, to make gsm calls and
send text messages.

And I can get my cellphone to talk to my headset, speaking through the
headset and making calls.

And I can get my headset to talk to my ibook, again speaking into the
headset and listening on the headset or on the mac speakers...

BUT, is there any way to use my cellphone as a headset? so I could
talk into the mic on my cellphone and it go via my ibook over skype to
my friends? And I would hear their voiced on my cellphone... this way
I can link my cell to my ibook and make my skype calls without faffing
with the headset.

Sounds easy, huh? Has anybody out there managed to do this?

big thanks
Alex