Your problem is that no matter how much you compress it or hide it, eventually the browser has to interpret it. The best you can do is renaming all variables to meaningless random vars, and removing all comments and whitespace.
A few good tools:
- http://www.dev411.com/dojo/javascript_compressor/
- http://javascriptcompressor.com/Default.aspx
- http://developer.yahoo.com/yui/compressor/
