Maybe I'm wrong about this, but it looks like you don't verify the name returned by gethostbyaddr. You probably don't need to if it's just for web statistics, but if you, like me, are in the habit of looking back over old code to remember how to do something, it might be a good idea to put that in or at least put in a comment about it, in case you need a more certain resolution for the ip in the future.

There's a discussion of this in Perl Cookbook, section 17.7 ('Identifying the Other End of a Socket'). It basically says that because a name lookup goes to the name owner's DNS server, there's the possibility that the machine could give false information. Using gethostbyname and comparing the answer to find the original ip checks that. It also mentions that it's still not 100% secure.

I wish I'd checked the code catacombs yesterday before I wrote my own version of this for exactly the same purpose. Bleh. Bad Kudra.