The ultimate tool to seem very geek (and amongst geeks, really cool), a huge book from Yggdrasil Computing. Not a very useful stuff, though, it's simply HOWTOs catted together in a massive 1500+ page book printed on Bible-like thin paper. It's as expensive as hell and becomes outdated fast, but man, the face of friends and/or girlfriend when seeing you reading this worth everything, really. I was even asked once to read a good-night tale from it...

Oh, and another strange fact: I have this book from the local town hall's (non-public) library (Mum works there), and has a date of 1995 stamped in it. Why, tell me why (and inspired by whom) would a Microsoft-user town hall in Hungary buy such an expensive book about Linux in 1995??