For those of you who are into aircraft ... here's a link to photos of aircraft approaching the sound barrier, or flying supersonic, and forming the characteristic Prandtl-Glauert condensation cloud.
This site is mostly about the fluid dynamics associated with Prandtl-Glauert condensation clouds but it has links to other sites with some great photos. Just surf the links.
http://fluidmech.net/tutorials/sonic/pr ... clouds.htm
http://www.steehouwer.com/
http://www.wilk4.com/misc/soundbreak.htm
http://chamorrobible.org/gpw/gpw-20040817-English.htm
Don