Java Script Obfuscation

JavaScript Obfuscators
http://www.geocities.com/SiliconValley/Vista/5233/jmyth.htm

http://www.quadhead.de/jss.html

http://rzr.online.fr/jammer.htm

HTML obfuscators that work on JavaScript
HTML Guardian

Other Approaches
Attempts to secure the code away from human eyes, with passwords, cookies, etc. This page lists a number of these, as well as crackers for them:

http://www.woodmann.com/fravia/compilsee.htm