use Module::Versions::Report;

...and any code you want...

This will run all your code normally, but then as the Perl interpreter
is about to exit, it will print something like:

Perl v5.6.1 under MSWin32.
Modules in memory:
attributes;
AutoLoader v5.58;
Carp;
Config;
DynaLoader v1.04;
Exporter v5.562;
Module::Versions::Report v1.01;
HTML::Entities v1.22;
HTML::HeadParser v2.15;
HTML::Parser v3.25;
[... and whatever other modules were loaded that session...]