Registered: Jun 2004
Location: Corvallis, OR
Volume up/down and mute are available as key codes. Set some event to a key stroke (or possibly key hold) and scroll to the bottom of the keystroke list to find them.
I've set the invisible keys next to F10/11/12 (available on the TouchStream) to these. You might be able to work out a good gesture set, too, perhaps.
The following media-related keystrokes are listed (I think they may be defined by Windows; I'm running XP SP2):
The rest of the special buttons from MS keyboards show up, too: EmailReader, Web Search, Web Home, Web Back, Web Forward, Web Stop, Web Refresh, and Web bookmarks.
relevant email welcome at [dave aasv org]