AFAIK most of minificators also shortened variable / function names - are there any that don't do this? (take a look at minified jquery.js for instance)
Css get minified by removing whitespace because the keywords are important.. Javascript can have some magic done to it to reduce character count because only the consistency of the keywords matters.
Otherwise yeah, you can just run it through a whitespace-remover. There are also often options on e.g. the YUI compressor: http://refresh-sf.com/yui/ and Google's: http://closure-compiler.appspot.com/home