What are some alternatives?
When comparing EarTrumpet and Volwheel, you can also consider the following products
Volume2 - Volume2 is an advanced Windows audio mixer, a complete replacement for the standard Volume Control.
Power mixer - Power Mixer is a complete Windows volume control replacement.
Background Music - Control the audio on your Mac apps from the menu bar
Volumouse - From authors website:
Audio Sliders - Volume Control replacement that is five times smaller than its Windows counterpart.
3RVX - 3RVX is a skinnable volume display and controller.