Exuberant ctags should be able to output a TAGS file which emacs can grok enough to let you jump from calls to definition. Also possibly of interest might be ECB which understands Perl as one of the languages and gives you a tree of declarations and what not to jump through code.
(Slight disclaimer: I've been Switched™ to OS X for about a year now so my (x)emacs-fu is rusty, but this was the stuff I used when I was still an active xemacsian).
The cake is a lie.
The cake is a lie.
The cake is a lie.