Is there a way to get those dandy little extra buttons on my internet keyboard working under Linux? It's a standard Gateway internet keyboard (PS2, not USB). I loved being able to start up common programs just by pushing a button on my keyboard.

Yes there is.
I set this up on my previous install (Red Hat 7.1), haven't found where to do it in Suse though.
Every key sends it's own code. Using the program xev you could see what events are triggered in X. Now push your internet key and you will see a keycode. Write this code down.

Now you will have to map this keycode to something. I used F13 and up.
This information is entered in the Xmodmap file found in /etc/X11/ dir.
Follow the same syntax as you can see the other keys are.

You may have to log out and in again for the change to take effekt. Now you have a new "function key" F13. This you can map to an event in your window manager.

I probably have the same keyboard as you and I have not been able to find a layout that works with it (other than the standard 104).

My gateway keyboard is:
PS/2 Millenium Multi-Function Keyboard (104 keyboard keys with 11 extra hot keys)
Manufacturer model (Microsoft): RT3602 V:5STW
Vendor part number (Gateway): 7002737

None of the 'Microsoft...' and 'Generic...' Xkb layouts that I have tried so far have worked. So, I can not have two languages layouts.

Also, I guess we need to do some sort of manual mapping for the multimedia and extra keys.

Unfortunately, 'hotkeys' conflicts with xmms.