You should really read Isaac's comments on the blog: http://blog.greenfelt.net/2009/09/01/caching-javascript-safely/#comments http://blog.greenfelt.net/2009/09

You should really read Isaac's comments on the blog: http://blog.greenfelt.net/2009/09/01/caching-javascript-safely/#comments http://blog.greenfelt.net/2009/09/01/caching-javascript-safe... They are really insightful and expose the knowledge gained from a lot of work he's done at Yahoo! on this subject.