I've just put a new bookshelf in the bathroom and I've been loading it up with books suitable for reading on the toilet. It's a tricky decision process. So far I have: a dictionary of film quotations, a dictionary of musical quotations, an encyclopaedia of R&B music, Halliwell's 'Who's Who in the Movies, 'Getting Even' by Woody Allen, 'Letters from a Nut' by Ted Nancy (aka Jerry Seinfeld), 'How to Draw a Radish' by Joy Sikorski, the 'do-it-yourself genius' books of amazing facts and the rough guide to cult movies. Oh, also the complete guide to 'The Simpsons'.
There are also a few old issues of Empire magazine and the Times Magazine section (I only read Giles Coren though).
So that's it. Not very varied, is it? Nothing particularly educational. My parents have the Pears Encyclopaedia in their toilet - that's how I memorized the map of Africa. They got learning into me through the back door, if you'll excuse the phrase.
Suggestions for good toilet reading are welcome.