Recently, Matt Cutts posted a short and sweet blog post about Google's use of the Meta Keywords tag. He confirms what I wrote on in the Meta tags section on page 95: "Keywords largely abused so it's ignored by Google and most other engines."

He also commented in response to a reader that the description meta tag doesn't affect ranking. Specifically, he says, "So changing your meta description tag won’t make your website rank higher." He does say that Google uses it as the snippet (description of the site in the search results). So, while it won't help you rank higher, it's still important to your Google traffic. If you have a good snippet, you may attract more visitors to your site.

As always, Matt is a fount of info on how and how not to rank better in Google. Thanks, Matt!