I bought a TechnoTooth from Pedro's Garage.
TechnoTooth
Apart from a bit of a wiring issue (my car apparently has a later-model factory radio) that was quick to fix after 3 minutes on the phone with Pedro, the install went very smoothly.   The device integrates with the existing radio and gives Bluetooth connectivity.  It also includes a microphone to route up to the visor area for hands-free calling.   
I know this is a product that has been around a while and has probably been discussed before, but I am very happy with the product and the after-sale support.   The ability to stream my music via Bluetooth, in addition to nav and phone calls, is a great upgrade, and this was a very cost-effective way to get it done.   I just didn't feel like pulling the head-unit and dropping an aftermarket system in.   I've done plenty of that, and just preferred not to here.