edit: New update....
The bluetooth headsets are being returned today.... for the reason that if you wander away from your helmet for more then 3 mins, the devices will turn off. Turning them back on involves pulling the helmet ear pad to get to the headset as well as getting to the sender (which is tucked away within your gear) to turn both on. Do this while a large number of riders are waiting for you to ride and it becomes apparent that this isn't working out.
Also the 9 hour life won't last a good solid all day ride, despite all the starbuck stopovers.
You are constantly worrying about the distant between your helmet and the sender, the battery life, as well as occasional music drop outs (not many), and no battery back up, the bottom line for these devices are not worth the money.
Well with time on my hands over the last two days, I decided to pick up a camera and while I was at the Sony shop, I found two items that seemed to be worth investigating; the Sony portable Stereo Transmitter and the Wireless Stereo Headset Ear Clip Style. You can also get the Bluetooth Ear bud style.
The units has 11 hours of playtime (more then enough for most group rides ).
This eliminates another minute when preparing to get back on the bike.
No dangling wires from the helmet. Just slip on the helmet, press the remote play button and the music starts playing. The ipod and transmitter can be tucked away safely within an internal pocket.