Here is another link.
http://www.earinc.com/m-motorsports.php
The Australian Distributer was at the recent Mbike show and was doing a booming trade.
They place a small foam plug in your ear, then they take a syringe full of silicone rubber with a hardner added and fll your ear canal, let it set and off you go. If you want they will add wires to plug into your mp3 player.