Meta Keyword Tag

How does the meta keyword tag further your Search Engine optimization efforts? Although most crawling search engines no longer support the tag it is still a useful way to reinforce your keywords on the Crawlers that do, namely Inktomi and Teoma. AllTheWeb, AltaVista and Google ignore the tag. However, it should be pointed out that any benefit derived from the meta keyword tag is minimal, many SEO's experienced in Search Engine Optimization no longer use the tag.
If you have a page about search engine optimization you will naturally repeat the term "search engine optimization" at various places through your body text. Including the term "search engine optimization" within the meta keywords tag will help boost your page for those terms in the search engines that still support the meta keyword tag.
The text in the meta keywords tag works to support text in your body copy. If the term "search engine optimization" does not appear on the page, then placing it in the meta keywords tag is unlikely to boost the page to any great extent for the term, and indeed may be seen as spam.
The meta keyword tag is also a means to include synonyms; different and common misspelling of words that appear on the page. If you had a page about "website design", people may instead search for "web site design". Having the term in your meta keywords tag may increase the odds of coming up if someone searched for "web site design".
Another example would be the different spellings of optimization (if you are in the US) or optimization (if you are in the UK or Australia) You could use both terms on the page but this method may end up diluting your keyword relevancy. You would however, greatly increase the chances of being found if you created two unique pages, one using optimization throughout the page and the other optimization. The same goes for the previous example.