shanew the way you're doing it is probably wrong just for the simple reason that youre putting to much focus on the keywords. as luzie suggested, meta KW and Desc are not that important to search engines as they used to be. I would suggest that you put in the same effort into writing more and better articles than the tags.
and make sure you refrain from using the socail bookmarking sites like digg for spamming purposes. If you simply bookmark the articles there with tags, then its all bad karma as you might be knowing. which brings us back to what we discussed earlier.
luzie said - "Absolutely true. Metatags description, abstract, keywords and the like are not considered for ranking. It's not so much for spamming, but because meta-tagging is not needed anymore, the search engines being able to recognize and extract their own keywords and conclusions directly from the viisible content."