You seem to be under the impression that forking will use more resources than threads. Usually just the opposite is true with perl threads on a unix-like platform. I strongly recommend you try forking instead.
Comment on Re: ithreads picks fight with LWP::Agent; everybody loses
Uh-oh. I'm actually doing this the other way around; the original code went crazy with forks (I'm trying to get a LOT of HTTP requests running concurrently) and quite simply brought the server to its knees. Thanks for the warning; it'll keep me from committing seppuku if it turns out I'm wasting all this effort barking up another wrong tree.