I recently had a few queries about URL’s, using www, not using www, using both and forwarding different names. In summary, all of the questions were pretty much the same.
Q. What’s the difference they all end up at the same place don’t they?
A. Short answer: Visually yes, but not in the eyes of the search engines.
Variations of URL’s that return the same content are bad Mmkay. Multiple URL’s, at first glance, seem to be a good idea. I know what you’re thinking. “Hey, it’s more access points to my site. More ways to get there means more traffic, right?