was rummaging around the m109riders message boards and ran across a thread with this link in it. It really seems that it would be a good investment to me. http://www.wbaltv.com/news/14328936/detail.html
They were just talking about this on the radio on my way into work this morning. Seems worth looking in to. Wonder what the difference is between the vest and jacket...
Did a little searching. Looks like the vest is what inflates so even with a jacket the arms are not padded although some have armor in the arms. Seen them as low as $200 for the vest, mesh jackets in the $240 range even some with full leather. They are triggered by a cable you attach to your bike frame. When you fly off it inflates.
This of course leaves me wondering how many times would I set it off forgetting it was attached.