For those who regularly use Perl, you might be interested in two new books that show how to use Perl in more Lisp-ish ways.
The first is Higher-Order Perl, by Mark Jason Dominus. It's basically closures on steroids for Perl. Topics covered are recursion, iterators & generators, memoization, higher-order functions, combinator-style parsing ala Haskell, and domain-specific language generation. It is chock full of goodness.
Mark is a long-time Lisp and Haskell user and mentions influential books in his preface such as Norvig's PAIP ML for the Working Programmer, SICP, and Bird's Introduction to Functional Programming.
Here's what he has to say about Lisp in his preface:
Around 1993 I started reading books about Lisp, and I discovered something important: Perl is much more like LIsp than it is like C. If you pick up a good book about Lisp, there will be a section that describes Lisp's good features. For example, the book Paradigms of Artificial Intelligence Programming, by Peter Norvig, includes a section titled What Makes Lisp Different? that describes seven features of Lisp. Perl shares six of these features; C shares none of them. These are big, important features, features like first-class functions, dynamic access to the symbol table, and automatic storage management. Lisp programmers have been using these features since 1957. They know a lot about how to use these language features in powerful ways. If Perl programmers can find out the things that Lisp programmers already know, they will learn a lot of things that will make their Perl programming jobs easier.You can read more about the book at this interview.