Has anyone had one, used one or heard one? I'm getting annoyed with people who walk out in front of me when i'm cycling. They're usually on their stupid mobile phones or walking a dog on a 20ft long lead. I've tried bells but they're a bit timid and do they look good on a road bike?, maybe not! I've seen these http://www.google.co.uk/products/ca...a=X&ei=auQFUNquBYzEtAbw0bSFBw&ved=0CFoQ8wIwAA and they look like they might wake the dozy phone checkers and dog walkers up before they step into my path! Any thoughts?