Next to that, also the size of the individual files is important. Minimizing these files can be very usefull. Of course you can minimize the individual files with tools like http://www.csscompressor.com, but it makes the files much less readable.
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This is a very usefull technique, can save a lot of loading-time. The downside is that it sometimes breaks functionality, as some functions require immediate execution of the script to function well. Make sure you test!
Load resources asynchronously
Whenever possible, try to load resources asynchronously, so that they do not block further loading of the site. One example could be to load your Google Analytics asynchronously, they offer a snippet for that on their pages that you can use to replace the standard script.