Also, with mozilla you can simply insert a new username@ after the ":" of your protocol like
this "http://email@example.com" and it will then proceed to prompt you for a username & password.
Now you can enter your original username and a bogus password which it will now remember.
Yes, this is a hack, but it will do what you want. There may be a better method, but that is
what I came up with quickly. I was surprised that it was not stored under the password tab in
the options menus.