I've haven't found a great notebook app yet either but the problem lies more with my clumsiness with the multitouch keyboard than the app. I carry around one of these these tiny Minerva notebooks, shoot pics of the pages and organize in Evernote. The notebooks only have 48 pages, which is more than enough for an outing, they are about as thick as a matchbook and fold up like up too. Each page is perforated at the top and I often draw on them to hand out in lieu of business cards.

Beautiful website!