I you submit to article directories as part of your SEO strategy, it's always best to write an article specifically for the directory. You don't want articles on your website duplicated all over the web, otherwise you dilute the potential for your page to be ranked highly. If you have trouble finding the time to write articles, you can outsource it for as little as $4 per 300-word article.

Try elance.com or rentacoder.com for outsourcing. I currently use Pajama Team and have been very happy with the results.