Handlebar mounted speakers

I ride my bike a lot and I was thinking about getting speakers for my
bike to use with my discman. I thought about getting some small
speakers that I could attach something to and mout them on my
handlebars. I looked at Sonic Impact's Gen 2 speakers -
http://www.si-5.com/frontEnd/cm_prod...p?productID=15 - but I
don't know if these are any good for outdoor use. So does anyone know
of a small, good sounding pair of speakers that would be good for such
use?

Thanks, Dan