Mac OS X: Switch key mapping between S- and M-

[Florent Georges]

  Hi,

  I've finally succeeded building GNU Emacs 23.1 on Mac OS X
10.6, thanks to you!  But a new "feature" is that keys like S-c,
S-x and S-v are mapped to Mac OS equivalent (S modifier is mapped
to the "command" key, so those are the same commands as in other
Mac OS applications for copying, pasting, etc.)  The worst of
them being S-q mapped to quit when I am used to use it as M-q
which I use all the time!

  Is there any way to map S-* to M-*, or even better to change
the mapping between the "command" and the "alt" keys?
(resp. mapped to the modifiers S- and M-)  I am used to Emacs
bindings for years, and this is really confusing to have Mac OS
mappings interfering with my fingers memory...

  Regards,

-- 
Florent Georges
http://www.fgeorges.org/