I like to listen to music or podcasts while I play, and sometimes I skype with my friends. To do this I turn in-game sound down. However, booting up Diablo and in the general BNet screen, the volume is WAY too loud and I can't hear my podcasts/skype/people yell at me on skype for the loudness. Any way to adjust the chat volume?

CTRL + M turns off the lobby music.

if u have vista u can adjust the volume on a per-program basis. just alt tab and go to your volume properties speaker thing next to the time in the lower right of your taskbar