How do I hide the "Saved Passwords" button in Firefox?

This little button is the scariest thing in Firefox as far as I'm concerned:

I realize that passwords saved in web browser must neccearilly be stored insecurely, usually with a reversable hash, but most people don't know how to reverse this. I'm really worried about a friend, family member, or a co-worker on my computer just going in there and seeing my passwords -- it'd be trivial for them to do. Is there any way to at least hide this button?

If you set a master password you'll be prompted to enter it before it will show you the saved passwords. Seems like an easier solution than always having to do a custom chrome.

The best way I've found to hide this button is to create a custom userChrome.css file for Firefox. First, find your Firefox profile folder:

Vista/7: C:\Users\USERNAME\AppData\Roaming\Mozilla\Firefox\Profiles\SOMETHING.default
XP: C:\Documents and Settings\USERNAME\Application Data\Mozilla\Firefox\Profiles\SOMETHING.default
Mac OS X: /Users/USERNAME/Library/Mozilla/Firefox/Profiles/SOMETHING.default Linux/Unix: /home/USERNAME/.mozilla/firefox/SOMETHING.default

(more info on finding this at a MozillaZine Knowledge Base article)

Then go into the "chrome" folder. In here make a plain text file called "userChrome.css". Put the following into this file:

#showPasswords, #security-view-password { display: none; }

This will hide the "Saved Passwords" button in the Firefox preferences. I've gone so far as to set this userChrome.css file to hidden to make it less obvious that this is how I've hidden that button.

Obviously this is not fool proof. With enough time and effort, someone could still get into your passwords for instance by changing or removing the userChrome.css file. Still, it beats just leaving the door wide open.

You can set a master-password. If a master-password is set, you'll need to enter it when you want Firefox to remember your password and when clicking the "Show Passwords" button.

you can read more about it at here