I created a free Meta tag generator yesterday.

To use it, paste in your html or plain text and it will output both your keyword and description meta tag, and you can decide how many keywords to display. Sometimes common words will show up, so I'd suggest choosing a number that is slightly higher than you want and then manually removing the common words.

Thanks,
Brian

Looks like a nice tool for html writers, but it does not parse php, so most of the keywords are php instructions for mine.