(Meta) Key Words are almost always ignored by search engines since Website Developers realised that putting "Pamela Anderson" into the keywords would get them more traffic.
That said, they may still be worth 0.1% of your pages' ranking.
Because of the aforementioned Bay Watch star, the search engines now check to see if the words in your key-words are actually on your page.
If the words are NOT on the page itself, then this counts against you, as the search engine thinks you are "trying a Pamela".
The amount you are marked down for this may be more than the 0.1% it was worth in the first place. So always check that your Meta Key Words are indeed on the page...
For more help with Meta Key words and promoting your website, please contact us for a free consultation.