As for headsets, the original jawbone has now been replaced with a jawbone 2 - which reviewed really well, but I couldn't get a great fit with it so I returned it. The other highly rated one I'm interested in trying, but haven't yet, is the new BlueAnt Z9i, which replaces their old model, the z9.
So to comply with the new CA law, I purchased a BlueAnt Supertooth 3 hands free device. It clips on the visor, and seems to work fine. It works with voice commands, which is kind of cool. It does pick up ambient noise, but I've had the window down and carried on converstations - though not at fwy speeds. I don't usually have the windows down on the freeway anyway. So for now this is working well, so I'm in no rush to try a different device.
You can check it out at
www.myblueant.com