SpotiMy - Play/Pause and Next/Previous functions for Spotify directly on your Menu Bar!
Volume2 - Volume2 is an advanced Windows audio mixer, a complete replacement for the standard Volume Control.
Muzzy - it’s a tiny and gorgeous iTunes companion that lives on your menu bar. For Mac OSX, its free!
Sound Control - App-specific volume control
Owlead - Grow your Twitter with valuable followers, effortless
Power mixer - Power Mixer is a complete Windows volume control replacement.