1)   Power Mixer 2.0
Power Mixer is a complete Volume Control replacement that lets you easily change the sound volume by simply rotating the mouse wheel or by using hot keys. It includes an audio mixer, a scheduler, OSD, command line support, customizable presets.

 2)   VolumeTouch 1.1
A freeware replacement utility to replace the Windows speaker icon. Controls the master volume. Supports various keyboard and mouse shortcuts. Supports mute/unmute, access to andvanced controls, skins and more. Easy configuration.

 3)   WheelsOfVolume 1.00
Freeware application that allows you to control the volume of your computer using the mousewheel. When the mouse wheel is clicked (middle mouse button) the sound will be muted. Extremely intuitive in use and uses very litle resources.