Examples of lazy evaluation techniques in Perl 5?

I find that one of the most interesting features of both Haskell and Perl6 is the ability to defer calculating values until they are actually needed.

Perl5 on the other hand likes to do everything immediately, but from what I can tell, contains all of the necessary primitives for lazy evaluation. Those are:

• taking a reference to @_ in a subroutine creates an array reference that is aliased to the identifiers in its argument list, even if some of those identifiers do not contain values yet.
• returning overloaded / tied objects from such subroutines that hold \@_ internally, and then dereference it when needed. (and there are various CPAN modules that abstract away the tie/overload details)

I've been experimenting with various lazy programming techniques in Perl (I have a module in the works that implements a fair bit of the Haskell Prelude in Perl5 (things like co-recursion: $_ = list 0, 1, zipWith {&sum} $_, tail $_ for my $fibs; to define the Fibonacci sequence are already working)). But I have a feeling that there are some subtle bugs hiding in the code that may manifest when the functions are used in larger expressions / programs.

So I am wondering if there are any good examples (CPAN / blogs / books) that anyone knows of that employ Haskell/Perl6 like laziness in Perl5? In particular, I would like to read through any code of significant size that employs this type of laziness.

I would also be interested to know if anyone has run into any gotchas or intractable problems surrounding the implementation of lazy evaluation in Perl 5.