EarTrumpet - Volume Control for Windows
Volume2 - Volume2 is an advanced Windows audio mixer, a complete replacement for the standard Volume Control.
Volti - Volti is an GTK+ application for controlling audio volume from system tray/notification area.
Volumouse - From authors website:
KMix - KMix is an application to allow you to change the volume of your sound card.
Volume Scroll - Volume Scroll lets you control your main volume by hovering with your mouse cursor over the top...