Perl is so rich that very few of us appreciate all the productive uses of all of Perl's features, especially outside the problem domains in which we are comfortable.
With the demise of The Perl Journal (long live The Perl Journal!) and the way that other mags are stuffed with Java, Python and even Ruby (which I admit to quite liking) it's not obvious how to stay fresh.
Obviously reading and occasionally wading into PerlMonk discussions is one useful tool to keep one's mind open.
Another I do from time to time is to run through some random quesions in snowdrift.org's Perl Test.
What do other people do to hone their Perl skills and their knowledge of useful CPAN modules?