^^^ this. Sprockets is a good way to do this if you're using Rails. If you don't need something quite as sophisticated, Rails has built-in asset caching that wi

^^^ this. Sprockets is a good way to do this if you're using Rails. If you don't need something quite as sophisticated, Rails has built-in asset caching that will combine your JS and CSS files into a single file automatically by just putting :cache => "identifier" on the asset tag helpers. You should probably still try to use the major CDNs for very popular libraries like Prototype, jQuery, etc. These are more likely to pull from cache and not incur any additional transfer time.