In Ubuntu 8.10, Inrepid there is no obvious way to create a keyboard shortcut to run a command or open a program or similar. However, I like to have the terminal on a keyboard shortcut (super ~) so, here is how to set up creating a keyboard shortcut in ubuntu 8.10.
press alt-f2 to open the launcher, and launch “gconf-editor”
then go to Metacity> keybinding_commands
choose any of the commands (I didn’t have any taken already, so I chose command_1) then set the value to the command you want to launch (so for myself, I changed the value to “gnome-terminal” to launch the terminal)
Then go to the folder Metacity > global_keybindings
select the “run_command_*” equivelent of the command number you chose in the first step (I would select “run_command_1”) and change the value to the hotkey that you want to launch that command. So for my command, I want it to be the windows key, and the tilde (~) key, I set it to “<Super>dead_grave” the windows key is always “<Super>” and because I use the international (with dead keys) keyboard layout, I had to set it to “dead_grave” instead of regular “grave” or “tilde” (grave is the ` character, or what you get when you press the tilde key without a shift)
You could also set this in compiz general keybindings, but I prefer to use the gconf-editor because I can make a key run any command I want, and I don’t need to have compiz installed/running for it to work.
Note: this will only work in Gnome, to do a similar thing in any or all window managers, follow this guide: http://ubuntuforums.org/showthread.php?t=79560