What you are looking for is PersistentPerl. This will keep the perl interperter in memory, and keep your perl code compiled. It provides almost all of the speed benefits that mod_perl offers without needing to be integrated directly into Apache.
There is also a mod_persistentperl module for Apache (and Apache2) to avoid the need to fork a process for each request (which is how CGI works). This means the only extra overhead over mod_perl is a socket connection to the PersistentPerl daemon for your script.
Other benefits of PersistentPerl are that you can run multiple scripts under the same interpreter, and you can use the suexec features of Apache and run your code under a different username (unlike mod_perl).