Official Google Webmaster Central Blog: Google does not use the keywords meta tag in web ranking.
This is an article that states that Meta-Keywords are not looked at at all by Google, and that it is not useful to have them.
This is an article by google that says that they do use the meta tags:
I recently ran a test on a site that was ranked on the 26th page of google for a search term. I updated ONLY the meta keywords, and watched it jump to PAGE 2!!! (within 24 hours)
So the question has been asked if meta tags are important? I would recommend using them, and it is best to follow the practises that google suggests. Here is a link to the protocol that Google suggests:
http://www.google.com/support/webmasters/bin/answer.py?hl=en&answer=79812
Even if they are not used, it can not do your site harm to have relevant keywords within the meta-tags. It can however hurt to have irrelevant met-tags, as shown from the article above. Please ensure that you are not running a noindex or a nofollow tag if you want to rank well in the search engines.
If you have an opinion, I would love to hear it.