In reply to Angie Lester:
Hiya,
I bought a couple of these recently for me and the misses. I don't know off the top of my head what make they are but the one's we've got are basically a couple of walkie talkies with helmet speaker/mic's and a button to press on the handle bars. Cost about £85 for the lot. Took some getting used to holding the button in while riding etc but they seem to work ok at low speed.
Only problem is anything above 40 MPH and you find yourself trying to shout over the wind noise, and the other side can't hear you anyway for the same reason.
You can get voice activated ones which may be better but could also start transmitting automatically at highish speed due to the noise.
Some recon they are tested at high speed but I recon you would need a really decent helmet to stop the wind noise being a problem