In the last month I've fixed several bugs in this great module, B::Deparse. For those who don't know, B::Deparse turns a Perl program into an equivalent Perl program. You'll say, cat(1) does the same, right? But B::Deparse, quoting the docs, "generates perl source code, based on the internal compiled structure that perl itself creates after parsing a program." This module is not perfect, but it has several interesting uses (serialization of subroutines, de-obfuscation of programs, clarifying obscure precedences). And hacking on it is very pedagogical about Perl 5 internals.
The next thing I'll have to do about B::Deparse is to add support in it for the new \[...] prototypes. -- In fact I have a lot of things to do about Perl and other programming-related stuff. That's my New Year Resolution : doing things (instead of not doing things, you know).