I'm a convert to paper, having carried a Palm of one generation after another for the last 10 years. But they're just too bulky, not quick enough, and too hard to randomly flip through the accumulated information. (Please don't offer advice on fixing them; I'm in IT support and have gone through all the love-hate cycles with PDA's I can stand. And my phone is _just_ a phone.)
So I found these notebooks and fell in love. I keep one in my pocket at all times and am always jotting down notes, lists, diary entries, reviews, URLs, passwords, etc.
My only fear was losing one, or spilling water on it and watching my water-based fountain pen ink become unreadable. Happily, we have a new copier at work that scans to pdf and emails. So once a week or so I send myself any new pages and have a permanent record in my email inbox if needed--best of both worlds.
The little pocket on the back has been very useful--holds my bus pass in a very convenient location for quick access; likewise a few business cards--no need for a pretentious separate case. And room left over for a few dollar bills to get my caffeine fix on the way in to the lab.
I tape my business card to the inside front cover in the hopes some kind soul will return it if I do leave one laying somewhere. On the black v. tan color? Black shows less wear; tan does allow one to write on the cover--but depending on the ink one uses, how close to the body carried, and perspiration, this may not be a Good Thing for one's clothes.