Best Practices for Speeding Up Your Web Site

1. Minimize HTTP Requests

2. Use a Content Delivery Network

3. Add an Expires or a Cache-Control Header

4. Gzip Components

5. Put Stylesheets at the Top

6. Put Scripts at the Bottom

7. Avoid CSS Expressions

8. Make JavaScript and CSS External

9. Reduce DNS Lookups

10. Minify JavaScript and CSS

11. Avoid Redirects

12. Remove Duplicate Scripts

13. Configure ETags

14. Make Ajax Cacheable

15. Flush the Buffer Early

16. Use GET for AJAX Requests

17. Post-load Components

18. Preload Components

19. Reduce the Number of DOM Elements

20. Split Components Across Domains

21. Minimize the Number of iframes

22. No 404s

23. Reduce Cookie Size

24. Use Cookie-free Domains for Components

25. Minimize DOM Access

26. Develop Smart Event Handlers

27. Choose <link> over @import

28. Avoid Filters

29. Optimize Images

30. Optimize CSS Sprites

31. Don't Scale Images in HTML

32. Make favicon.ico Small and Cacheable

33. Keep Components under 25K

34. Pack Components into a Multipart Document

See More:

http://developer.yahoo.com/performance/rules.html
http://www.phpv.net/html/1660.html