New Year's Resolution: learn another language

[Cody Pendant]

It's definitely not that I think I know everything there is to know about Perl, but I'm somewhere in the middle of the bell-curve, and I've decided that my skills in general are somewhat stagnant and I should try to learn a new programming language.

Other than Perl I've worked in PHP, JavaScript and XSL mostly. I came to Perl from web coding, so I know HTML and CSS. I have no CS background whatsoever. And I'm not looking to improve my career prospects.

What I wanted to ask the Monks was, which language will teach me some interesting concepts, something different that I don't know from working with Perl?

Or perhaps I mean, teach me a way of thinking that's different from/complementary to the Perl way?

Should I learn a language which gets me closer to the bone of what the computer's really doing and doesn't make things as easy as Perl? Or a language which is all about object orientation from the outset? What are these "closures" I hear about? Perhaps a language which uses significant whitesp-- no, that's crazy talk.