Hey, in the future can you not put an entire script in Perlmonks? Wait until someone asks you for a specific piece of code rather than dump the whole thing.

The answer to your question is going to be rather messy:

# cat foo.pl
# -----------
#!/usr/bin/perl -w
use strict;

use CGI;
use LWP::Simple;
1;

strace perl foo.pl 2> foo.pl.strace
perl -ne 'if(m/(\S+\.pm)/){print qq|$1\n|}' foo.pl.strace|sort|uniq|ca
+t -n
[download]

Produces (in short):

...
   149    stat64("/usr/lib/perl5/site_perl/5.10.0/LWP.pm
   150    stat64("/usr/lib/perl5/site_perl/5.10.0/LWP/Protocol.pm
   151    stat64("/usr/lib/perl5/site_perl/5.10.0/LWP/Simple.pm
   152    stat64("/usr/lib/perl5/site_perl/5.10.0/LWP/UserAgent.pm
   153    stat64("/usr/lib/perl5/site_perl/5.10.0/URI/Escape.pm
   154    stat64("/usr/lib/perl5/site_perl/5.10.0/URI.pm
   155    stat64("/usr/lib/perl5/vendor_perl/5.10.0/Encode/ConfigLocal
+.pm
   156    stat64("/usr/lib/perl5/vendor_perl/5.10.0/i586-linux-thread-
+multi/Encode/ConfigLocal.pm
   157    stat64("/usr/lib/perl5/vendor_perl/5.10.0/i586-linux-thread-
+multi/Log/Agent.pm
   158    stat64("/usr/lib/perl5/vendor_perl/5.10.0/Log/Agent.pm
   159    stat64("/usr/lib/perl5/vendor_perl/Encode/ConfigLocal.pm
   160    stat64("/usr/lib/perl5/vendor_perl/Log/Agent.pm
   161    XSLoader.pm
[download]

So, for a script that does nothing interesting and only uses two modules Perl actually checks for the presence of 161 modules. Looking at %INC only shows 37 elements for the same script, so I'm inclined to think that strace is giving me the bigger picture. Figuring out which modules you can live without should be a chore. I think you can save yourself the headache and just put all of the modules a script needs in a PAR archive and reference that.