I won’t go into too much detail on how to do this because I wrote a great post two years ago with thedetails on web graphic optimization. What I will say is this is a huge area of savings that many people do not utilize.
Google Speed Tools – Before getting into a few specific tools that I found you should definitely check out the list of tools and resources Google has put together it their hope to speed up the web.
CSSOptimiser.com – This free web tool will optimize a file or code that you copy and paste into it.
HTML & CSS Validation Tools
Another important aspect of good clean web living is making sure that your code doesn’t have errors in it and renders properly. These two tools are both standard in the Web Developer Toolbar for Firefox (just look under the Tools tab as the picture to the right shows).
Valid code might not provide as much speed benefits as compressed files, but it will most definitely affect the user experience. Valid code will render in any web browser, and it ensures a good user experience. Also, it hasn’t been proven that this has an effect on web crawlers’ ability to index a website, so I can’t see how it would hurt anything.