This is somewhat of a debate in the SEO realm, here is where I stand, feel free to post comments.
I was recently in a meeting with some other SEO counterparts and the subject of meta keyword tags came up. Personally I do not think they are useful anymore and anyone who still relies on them is wasting their time and out of tune with the most recent SEO realm. It is somewhat sad that I have seen many ‘SEO experts’ who learn SEO at a particular point in time and never seem to move on and keep up with latest trends.
As the conversation went on I stated that I considered meta keyword tags to be useless and its not even worth the time or effort to put them in. I still believe description meta tags are very important and should be used. However it is pretty obvious that at this point Google, Yahoo, MSN and other search engines do not want to be told what should rank well for certain terms, they want to do it via their own methods to provide the most accurate results according to what they think is relevant. The whole idea of a meta keyword tag is in total opposition to that fact. You are telling the search engines what you think your website should be ranked for. I personally believe that they actually either totally ignore the keyword tags at this point or will even weigh your website less for those specific keywords simply because you are trying to get ranked for them. I have experimented with this idea on a few sites and in most experiments when I took out the keyword tags the results were better than when they were in.
Post your comments please, I am interested in how others view this subject.

I agree for the most part. We do still however put misspellings in meta keywords and have seen that help occassionaly. With most search engines correcting your spelling for you that happens less though. It’s interesting that you noted an improvement by removing the keyword tag all together. Guess I’ll check that out myself, thanks.