Portions of some of Tom C's FAQ code appeared on screen in Sphere, as documented in the perl timeline (scroll down a bit to see the '98 entry).

Update: And then there was the perl implementation of Schneier's Solitaire in perl in Cryptonomicon ( ISBN 0060512806 ); of course one might haggle about that book being geared at a technical audience. :)

And another one: A Hymn Before Battle ( ISBN 0671318411 ), in which the main character is an ex-Army Sgt who's become a webmonkey and is described in passing as "a junior associate web consultant with an Atlanta web-page design firm. What this meant in practice was that he worked eight to twelve hours a day with HTML, Java and Perl." It's only a passing mention, but . . .