Google has released a whole microsite of speed tips for web masters. Some of them cover topics such as gzip and caching that, while well worth doing, are sometimes outside the control of someone using normal shared hosting.
Some simple tips that should be easy to implement are:
- CSS: Using every declaration just once
- Properly include stylesheets and scripts
- Reducing the file size of HTML documents
- HTTP caching
In fact, I’m contemplating going back to HTML after having been an XHTML convert for many years (a growing trend it seems, not XHTML 2 seems to be dead and HTML 5 looks like the future king).