I ran

perl -le "use Time::HiRes qw( time ); $t1=time; eval 'use LWP::UserAge
+nt; use HTTP::Request::Common;'; $t2=time; print $t2-$t1"
[download]

0.0728998184204102
0.0660429000854492
0.0670039653778076
0.0661859512329102
[download]

That means you'd save at most 70ms every time the script is run. I've waited longer than the time you'd save per day for a single PerlMonks page to load :) If you're that desperate for speed, you should switch to mod_perl, FastCGI, or similar