B. Mann Consulting

Here - then - is the big secret of search optimisation. Search optimisation isn't really about optimising for a search engine at all. It's about making good quality, cleanly designed, semantically-constructed sites that people want to read, that people can link to and which people can get the gist of in a few seconds. If you make a website well for human beings, then as a side effect - more often than not - search engines will spider it well and rank it highly. And they'll do this because it's the best site, not because you're trying to fool them.
plasticbag.org | weblog | Against Search Engine Optimisers...

Amen. Except, of course, that most people stumble over the first part: "making good quality, cleanly designed, semantically-constructed sites". In theory, it's easy. In practice -- get someone who knows what they're doing to help you.