Why common gimmicks don't work
You may have seen the sites that promise to submit your site to 10,000 search engines for one low rate. (99% of those search engines are virtually useless, why pay for that?) Some SEO companies use page cloaking, where one page is designed to be served to search engines and a totally separate page is served to visitors. Or link farms, where you take the same page full of links and add it to a bunch of different websites, trying to raise link popularity. Many of these methods will actually hurt your results in the search engines. Keyword stuffing, link farms, page cloaking - even direct site submissions - can actually harm you in the end. These methods are all considered "black hat SEO."
The search engines have a job to do. Their purpose in life is to return valid, meaningful results when someone searches for something online. They don't like to be tricked. Google, Yahoo and the other search engine companies hire thousands of genius mathematicians to find the sites that try to trick them, and when they find them, often times they will blacklist those websites. Which means no one will find that site through a search. Period. They will never return that site in search results, no matter how well optimized it is.