A few years ago, I bought a little pocket notebook (of the paper type, not the electronic type) that turned out to be a moleskine notebook which apparently has a long literary history and a very loyal fan base. Recently, I actually got around to actually using it after trying different ways to try to keep organized and sometimes the simple things work the best. PDAs and other stuff are always cool and fun to play with, but I'm having the most success simply using pen and paper to jot down notes and ideas.
I don't think you necessary need a "moleskine" notebook, although I guess the appeal is the practicality and well constructed bindings that my version has.
Doing a quick look online, I found the following pace to sell moleskine notebooks: