It's neat how many glitches people have found in these particular games. A couple other Pokemon "arbitrary code" hacks (in the Yellow version):

http://www.youtube.com/watch?v=3UnB1fomvAw (Pi day celebration)

http://aurellem.org/vba-clojure/html/total-control.html (proof-of-concept for a clojure-to-pokemon-to-assembly compiler)

A "normal" playthrough in which the author shows off various glitches (most without any kind of cheat device): http://lparchive.org/Pokemon-Blue/Update%2001/