Lion, not Leopard.
Maybe in the Keyboard control panel, if you actually showed where it says "empty trash" or "move to trash," it would have been helpful, because I have clicked through all of the shortcuts and I saw nothing related to the trash.
Sure, to just come up with something out of thin air, it is.
Also, I tried going to "Application Shortcuts" within the Keyboard control panel, clicking the plus, adding Finder and assigning the del key, but it wouldn't work. Apparently the keyboard shortcuts will only take in numbers and letters with the command, option, control or any mix of the above keys.