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Just go to http://iwl.me/ and put in a sample of your writing and voila! It tells you. It also can be different depending on what you put in there. I suggest prose vs. pointing out different web sites.
This site is trending right now, has gone viral, and is very popular. And fun!
My Personal Page and blog
The Nontrads site and blog
My Squidoo pages
Join me on Twitter as @betsyanne or @nontrads