Bluetooth for your helmet. I just got one and am able to listen to music streaming over the internet, GPS directions, and make/take cell phone calls. I also picked up an electrical connector that uses the trickle charger leads to feed a "cigarette" lighter adapter into which I plug in my cell phone charger. I never have to worry about a dead cell phone that way.
Already got the bluetootha few years ago.
Wish I would have waited till now because they are much less expensive now.