The yellow whistle in the AMK version of Doug's PSK is the Howler. http://www.upsideover.com/PhotoGallery.asp?ProductCode=AMK%2DWhistle

I EDC a standard Fox 40 around my neck (along with a squeeze light, a small compass, and my dog tags (never hurts to have first responders know your blood type). I haven't had a lot of problems with comfort or having the whistle bruise me. I make sure I don't get it under my seat belt when I'm in the car.