I now there is a 100 page thread on this ...
Blue Soleil works great.
BluePhoneElite2 works ... need more testing.
Have contacted Phone Amego (interested but doesn't do talk-through), Dialectic (nice guy but doesn't do talk-through and doesn't want to do a SDK license) and waiting for for BPE2 to return my email.
What I'm trying to do:
Basically, centrafuse/roadrunner for mac.
I know there is OpenMobile. However, no bluetooth at the moment (6-18-2010).
I have been searching for the past 2 weeks and just really haven't come up with any opensource or usable sdk for OSX.
So, I was hoping that somebody here could give point me in the right direction.