Writing down your passwords is dumb. But buying a logbook specifically to write them down, in a single place, which announces to the world that it contains all of your passwords? That's even dumber.
I spotted this logbook in Grand Passion in Clapham, London, just this weekend. It is for stupid people. (And yes, writing down passwords probably is more sensible than using a single, easily cracked password across all the sites you use. But my guess is that anyone using this book doesn't employ 32-characters random alpha-numeric text strings in their quest for security.)