Originally Posted by CommuterRun
Air Zound horn
The Air Zound bike horn emits a 120 decibel blast. The horn is handlebar mounted, and the air reservoir is attached to your water bottle cage. Easy recharging using either a bike pump or compressor. Each refill lasts for approximately fifty blasts.
This would get their attention.
http://store.nycewheels.com/air-zound-horn.html
Sweet. They should make a model with a smaller resevoir though, that thing is huge!