SubmitYourArticle.com will basically submit the same article to dozens of article directories for you. Alternatively they do offer a service - I forget the name - that will let you enter "variables" for an article so that it will then spit out a number fo articles based on the main one you submitted but using all the different word-combos you specify.
I.e. a sentence might be "This is how to get lots of article traffic" and then enter in extra variable so the next article would read "This is how I get plenty of visitors from my articles" and so on. It takes time but can be well worthwhile.
What can work well is to write your articles yourself (for quality purposes) and then outsource the creation of all the variables (which can get pretty boring!).