Volume Icon aims to be a lightweight volume control that sits in your systray

Volume Icon aims to be a lightweight volume control that sits in your systray.
It is often used in conjuction with the lightweight tint2 panel/taskbar.
  Features
    Change volume by scrolling on the systray icon
    Ability to choose which channel to control
    Several icon themes (with gtk theme as default)
    Configurable external mixer
    Volume Slider
    Hotkey support