EarTrumpet - Volume Control for Windows
IndieVolume - IndieVolume makes Windows programs use separate volume controls independent of other Windows...
Volume2 - Volume2 is an advanced Windows audio mixer, a complete replacement for the standard Volume Control.
SoundBunny - SoundBunny allows you to control the volume level for all open applications on your Mac.
Volumouse - From authors website:
KMix - KMix is an application to allow you to change the volume of your sound card.