Customizing Firefox keyboard shortcuts

I would like to be able to define arbitrary keyboard shortcuts in Firefox, including overriding some of the already built-in shortcuts (such as Ctrl + W to close a tab).

How can I accomplish this? I've found a few plug-ins that add specific additional short cuts, but none that are fully editable. I also couldn't find anything in any of the options menu to do so, though I'd be surprised if this was a feature that was built-in.

For reference (if needed): Firefox 3.0.12 CentOS 5.2

Use the Keyconfig addon

This extension will provide core functions for keyboard operation.

• Scrolling
• Tab Focusing
• Frame Focusing
• Finding
• Copy URL
• Clear HTTP Auth

Combining with keyconfig extension, you can set any shortcut key to these functions simply. If you operate Firefox by keyboard mainly, this extension will help you.

If you use AutoHotKey in combination with Wine, you can macro whatever shortcut you want!

AutoHotkey is a free, open-source utility for Windows. Automate almost anything by sending keystrokes and mouse clicks. You can write a mouse or keyboard macros by hand or use the macro recorder. Create hotkeys for keyboard, joystick, and mouse. Virtually any key, button, or combination can become a hotkey. Create custom data-entry forms, user interfaces, and menu bars. Convert any script into an EXE file that can be run on computers that don't have AutoHotkey installed.