*Banging head against table*
Thanks. I was searching for that precisely: sending back messages. Saw Threads::Queue yesterday and the words "Queue" dissuaded me from looking into the documentation.
Comment on Re^5: Should I use threads? Perl/DHCP/Radius
Still, in light of BrowserUks discussion, you should consider what the "main" thread is doing at all. I think that most of the work per-client can be done in a worker threads. Instead of just farming out the HTTP requests, I would farm out sending the responses to worker threads as well.