Volume?

I have a question. Maybe you can help me out. Ever notice when listening to music or watching videos on your computer the volume is all over the place? Some are lower, some super loud. Which is understandable because there are so many different sources and not everything is recorded at the same volume. Different web-sites have different default volume levels. Sometimes it's huge difference (e.g. 50% vs 100%). A lot of the time (mostly videos or MySpace) I find myself visiting a web-page and finding the volume slider as fast as I can so I can avoid getting my eardrums blown out.

Wouldn't it make sense to have an option to auto-normalize all the audio output to around the same level? Am I the only one who goes through this? Is there an existing program/application/plug-in out there that will do this?

Help would be appreciated. Thanks for reading. : )