Why not start participating in an Open-Source project? The easiest (at least it worked for me ;--) is probably to start writing or maintaining modules:

• first check that your company (and your boss!) are OK with releasing some of your work as Open-Source,
• then I am sure that if you use existing modules you can think of ways to improve them, either by adding features or by generally improving the code or the docs, contact the author and see if you can send her patches, or create a new module based on the initial one
• you might also have written modules for your own use, see if they can be made more general and used by others, check carefully if anything similar exists on CPAN, and if not then package the module properly, test it thououghly (on different platforms and with different versions of Perl), get a PAUSE id, and start uploading!

Then you will start getting emails of people using your software for all sorts of weird things, and believe me, they will give plenty of challenges to solve, plus lots of ideas to improve your module!

There are also plenty of other projects that could use a good Perl programer, just look at the OS Software you use nd contct the maintainers

Again: if you want to release a new module, please check that it does not exist already. Subscribe to the module-author mailing list (module-authors-help@perl.org should give you info on how to subscribe) and discuss it there.