http://www.perlmonks.org?node_id=90172
Description: Save this as ftplugin/perl.vim below a directory in your Vim runtimepath (type :set runtimepath to find it). This will allow you to search through included modules, use tags easily, and use the define-searching capability ( [d etc) to find subroutine definitions.

I posted this snippet in a message some time earlier, then found that I had to use Super Search to find it. Anyway, I figured I'd put it here.

" Vim filetype plugin file
" Language: Perl
" Maintainer: Ned Konz <ned@bike-nomad.com>
" Last change: $Date: 2001/06/20 20:23:37 $
" $Revision: 1.6 $

" Only do this when not done yet for this buffer
if exists("b:did_ftplugin")
  finish
endif

" Set this once, globally.
if !exists("perlpath")
  let perlpath = system('perl -e "print join(\",\",@INC)"')
endif

" Don't load another plugin for this buffer
let b:did_ftplugin = 1

" Set 'formatoptions' to break comment lines but not other lines,
" and insert the comment leader when hitting <CR> or using "o".
setlocal fo-=t fo+=croql
setlocal include=\\<\\(use\\\|require\\)\\>
setlocal includeexpr=substitute(substitute(v:fname,'::','/','g'),'$','
+.pm','')
setlocal isfname=A-Z,a-z,:,48-57,_
setlocal keywordprg=perldoc
setlocal iskeyword=48-57,_,A-Z,a-z,: 
setlocal isident=48-57,_,A-Z,a-z
setlocal define=^\\s*sub
setlocal comments=:#
let &l:path=perlpath
setlocal makeprg=perl\ -Mstrict\ -wc\ %
setlocal errorformat+=%m\ at\ %f\ line\ %l.
setlocal grepprg=rgrep\ -n\ -R\ '*.p[ml]'\ $*
map <buffer> <C-]> :exec ":tag /".expand("<cword>")