I figured this out. There is a post that covers working with extensions http://blogs.planetcloud.co.uk/mygreatdiscovery/post/How-to-extend-nopCommerce.aspx which was very helpful. Also, the backlog banners.txt has a step by step walkthrough on what to add etc.
I think I was looking for more of a "plug-in" feature here kind of like with Firefox. I can see how that would be quite difficult though.