Since Bluetooth is sketchy on the Hero, I figure it would be useful to have a list of peoples' experiences with different devices. If you have a Bluetooth device, please reply with it's manufacturer, name, the exact OS you are using, and how well it works. I'll try to keep this post updated.
Stock 2.1:
* Blueant Interphone (motorcycle helmet bluetooth) -- Works
* Jawbone Icon -- Works for both voice and A2DP
* Parrot CK3100 car kit -- Works for voice and enables voice dial
* Plantronics Voyager Pro -- Works
* 2010 Mazda 3 GT with Bose stereo system -- Works for voice but not A2DP
* Blue Ant T1 -- Does not work properly
Stock 1.5:
* Blueparrott B250-XT -- Works
* Foxl G-2 Bluetooth speaker -- Works
Fresh 2.3.3:
* Blue Ant T1 -- Does not work properly
Stock 2.1:
* Blueant Interphone (motorcycle helmet bluetooth) -- Works
* Jawbone Icon -- Works for both voice and A2DP
* Parrot CK3100 car kit -- Works for voice and enables voice dial
* Plantronics Voyager Pro -- Works
* 2010 Mazda 3 GT with Bose stereo system -- Works for voice but not A2DP
* Blue Ant T1 -- Does not work properly
Stock 1.5:
* Blueparrott B250-XT -- Works
* Foxl G-2 Bluetooth speaker -- Works
Fresh 2.3.3:
* Blue Ant T1 -- Does not work properly