I wrote a simple extension to LWP::ConnCache, which allows to somehow resolve keys before putting connections into cache.
Task is not very obvious until you understand that http://www.example.com/ and http://example.com/ are the same server and there is no need to open two connections if you want to get data from both sites.
Moreover http://*.livejournal.com and http://*.blogger.com are the same server.
how you do resolution – using DNS or using some other algorithm is left to developer.
Anyway – her it is: LWP::ConnCache::Resolving.