Correct me if I'm wrong, but I believe the original poster wanted to sort those strings by a substring (rather than just sorting the substring)? So while you folks are going about your fancy, big city mapping, you're throwing away part of the data he wanted. :-)

Update: Say, they do get reconstructed, don't they. Still seems like an awful lot of code to get what he wanted, though...

Update part deux: Woohoo! Thanks for adding me into the benchmark. :-)