(original at my bliki [ghastly term])
perlreref is a quick regex reference that brings together the gist of the disparate regex docs, thus giving people a single place to look if they just want to check something quickly.
I've thrown it around on irc and on the perl documentation list and taken suggestions. I gave it to p5p, and it's now in bleadperl.
There's a search.cpan.org-alike HTML version and the raw pod.