Well, I'm still just starting out in my geek career really, and decided to learn some Perl last summer in order to add another string to my bow -- and have an interesting and enjoyable challenge.
I haven't managed to get a Perl job, but my demonstrating understanding of REs and some other Perl techniques recently helped me get a job in a team standardizing on Python -- a language which I didn't know at all until after being offered the job (now studying!). I figure that at least some Perl skills are transferable.
And yeah, I know, I'm joining the Dark Side, but Python seems nice too.