If you're in the webbusiness, check out Peter-Paul Koch's article Keep It Simple: Fluid Thinking.
Think fluid. The WWW isn't a fixed medium. It's unpredictable. It will do unexpected things to your site, and the best you can do is go with the flow.
Keep it simple. The fluidity of the Web is not the problem, it's the solution. If you accept that your site will never be viewed exactly as you want it, you understand the spirit of the Web and its standards.