While on Holiday I bought a copy of Perl Hacks and this week I bought a copy of The Perl Testing Developer's Notebook. I didn't get time to read the Perl Hacks book while on holiday so it's stilling on the bookshelf unread. On my way home from work with the testing book I scanned it so I've started reading it even though it's the newer of the two.
I think the the Perl Testing book will fall into the special category of book, the "I wish I'd bought it before book". The last book I read like that was The Debian System - which I also wish I'd bought on the day of publication rather than waiting almost a year.