Out of sheer boredom, I was looking through the collection of logo submissions that were made as part of the StackOverflow Logo Design Contest, and I came across the following three designs, all of which look strikingly similar to the Server Fault logo:

This left me wondering. After StackOverflow started expanding and, among other things, created Server Fault, did it seek designs from proposed logo designs for StackOverflow, or is the similarity purely coincidental?