Some people incorrectly consider the title to be a meta tag. It isn't. The title can be very important if it's reflected properly in your content and linking structure.
The meta keywords tag has been treated as kind of a magic wish list for way too long. I think only Inktomi even looks at it now, and I can't imagine that it will overcome page deficiencies or improve your rankings enough to justify the angst that most newcomers expend on it.
My feeling about the meta description is that if an engine doesn't display it, they don't use it much in their algorithm. Algos are increasingly about visible text on the page or in links to your page.