local key swap? alternatives?

[Francisco Borges]

Hello,

I'm running Emacs 22.0.50.1 which I got from KarolyLorentey's multi-tty
branch, as I don't think this is related to multi-tty's patch I'm
posting here...

Long ago I came with the idea to swap keys in LaTeX buffers to be able
to type popular LaTeX characters without SHIFT, namely $%^&*()_{}.

So I thought of swapping ($,4), (%,5) etc but I wanted it only for
LaTeX-mode and never figured out how to perform a local key
swap. Instead I modified lisp/double.el to use doubles as (?4 "$" "4")
(?5 "%" "5") etc, e.g. hitting '4' once I get '$', hit twice I get '4'.
To get a decent compromise.

With my last compilation of emacs (22.0.50.1), this has stopped
working.

Two questions:

1. Is there an easy way for me to get this to work again?

2. Would anyone recommend another approach to the problem? Is there a
way to swap keys locally in Emacs?

                           -----

Thank you for your attention,
Francisco.

and BTW, thank you for Emacs ;-)