“Best Practices for Speeding Up Your Web Site” from the Yahoo Developer Network

Minimize HTTP Requests

• Combined files
• CSS Sprites
• Image Maps
• Inline images

Use a Content Delivery Network

Add an Expires or a Cache-Control Header

Gzip Components

Put Stylesheets at the Top

Put Scripts at the Bottom

Visit this terrific resource at http://developer.yahoo.com/performance/rules.html and read the detailed information.

HOWEVER, CodingHorror.com suggests caution when considering the advice from the Yahoo Developer Network:

“There’s some good advice here, but there’s also a lot of advice that only makes sense if you run a website that gets millions of unique users per day. Do you run a website like that? (If not, the Yahoo suggestions might not apply to your particular site) Avoid the temptation to blindly apply these “top (x) ways to (y)” lists that are so popular on Digg and other social networking sites. Instead, read the advice critically and think about the consequences of implementing that advice.

If you fail to read the Yahoo advice critically, you might make your site slower…”