Yeah, but the trick is in how we define "control". Just because it has always done through a slider doesn't mean it has to be that way, in every situation. When the user don't care about a precise volume but just a relative setting, a different interface could provide better control with less effort.
I have a design proposal for a really simple interface that would address many of the scenarios described in this thread and provide direct control with just a few clicks. I expose it here for your evaluation:
The interface idea is based around the "focus of sound" concept that I explained in a previous message in this thread: applications with the focus will play louder than those without it, thus creating a two-level relative priority set.
* The basic interface is an enhanced gnome-panel volume control. I've created a mockup:
http://www.flickr.com/photos/33364508 N04/3108031818/
This replaces the old, too small volume control with an always visible slider that allows for direct volume control with one click - important for users without mousewheel, using a laptop trackpad, a tablet touchscreen or an accesibility pointing device.
You'll notice that it also includes a "pin" button
By default,