Usually carry a small (3.5"x6.5") looseleaf note book. Not quite pocket sized, but carryable. Has the advantage of laying flat when opened, inexpensive and refill paper is available at any stationary store.
I am a professional photographer and do a fair amount of travel so have gotten into the habit of saving pages from each trip, as a record of expenses (for the tax man), hotel and restaurant notes, client notes, new friends, etc. When traveling overseas I add copies of passport, driver's license, eyeglass perscription, customs registrations of camera equipment and currency conversion tables.
Local B&N was out, but they did tell me that they stock only the small lined Moleskine book for $10.00. Was $12 at local art supply shop, and they had several differant styles.
Thanks for info, but will probably stick with my looseleaf book.