IBM ThinkPad T61
Use pacman to install xmodmap (xmodmap is included in the xorg-server-utils package), then create a text file ~/.Xmodmap and put this in it:
these are for the pager buttons
keycode 234 = XF86Back keycode 233 = XF86Forward
these are the music changing buttons:
keycode 144 = XF86AudioPrev keycode 164 = XF86AudioStop keycode 162 = XF86AudioPlay keycode 153 = XF86AudioNext
this is for the silver volume buttons:
keycode 160 = XF86AudioMute keycode 174 = XF86AudioLowerVolume keycode 176 = XF86AudioRaiseVolume
based on which Desktop environment you are in you will have to edit your hotkeys to get it working, if you are in a WM that doesn't provide this functionality, try installing xbindkeys
Assuming you are using alsa, open the XFCE keyboard configuragtion GUI (XFCE Menu > Settings > Keyboard) and add the following to the 'Application Shortcuts' tab. When prompted press the appropriate multimedia key.
amixer -q set Master toggle
amixer -q set PCM 2- unmute
amixer -q set PCM 2+ unmute
The previous two will adjust the PCM value by 2, if you desire you can change this number.