To echo talexb, be very wary of premature optimization; you can waste an obscene amount of time optimizing things that you know to be relatively inefficient but pale in significance against less obvious bottlenecks in your CGI.

Anyhoo, searching for 'optimization' turns up a fair amount of nodes, and I'm sure Super Searching would turn up even more, but two nodes (RFC CGI.pm refactoring and CGI::Simple vs CGI.pm - Is twice as fast good enough?) that might be of particular interest ...

    --k.