BTW, one of the best places to buy it is on Amazon.com -- right now going for $18 and free shipping if you buy enough qualifying stuff (like books, maybe).

I've seen that whistle and looked at others. What I want is a whistle or horn that is pitched low. Shrill sounds may get attention, but low-pitch commands more respect on the roadway. Maybe this isn't possible with light-weight components.

The other problem with whistles is how to get them from your lanyard into your mouth when you need them. When you most need them you're probably already in fast-moving traffic and don't want to make that motion. You can carry it in your mouth as you go through intersections ... if you don't mind drooling all over.