Blackberry 8900 and Treo 750

[staticv0id]

edit: Mod please move this to Bluetooth Central, not sure how I clicked on BB Connect.

I have a Blackberry 8900 (personal) and Treo 750 (Work). I absolutely hate the Treo, and would just forward calls to my BB but I don't want to use up all my minutes on my personal account for work.

I'm ideally looking for a way to pair my Jabra BT2070 with both phones simultaneously, which I know is not possible.

Is there any way to pair the Blackberry & Treo, so that when the Treo rings it uses the blackberry as a headset? I've already paired the BB to Treo, and it shows "Voice Gateway" as a service provided, but I can't figure out how to activate it in any way. If I pair the other way around, the Treo only shows DUN and Serial as available services.