I prefer simple solutions, speaking of which, you could start a socket server, then hijack/redirect connections with EXTRA_SOCK_OPTS... but you probably thought of that and don't like it for some reason (i don't like to write that much code :)

I'm using not only HTTP there, but also SSL/TLS, so...

OTOH, I just looked and saw LWP::Protocol::nogo / LWP::Protocol::PSGI 
+- Override LWP's HTTP/HTTPS backend with your own PSGI applciation

I think this is as close as you can get :)
[download]

Thank you, I'll check them out :)