Two things I would add to your list are a good map of the city and a phone book.

The phone book is only for your car or desk. I'm not recommending people carry the whole phone book. But the phone book contains a huge wealth of information, including maps, locations and phone numbers of government buildings, hospitals and nearly every shop. Okay, thats pretty obvious, but if you don't know it and you can't get to google on your Blackberry or Iphone, where are you going to find it?

A map is essential anywhere. Some cities are notoriously difficult to navigate with out one even in normal times. A map will help you find alternative routes and locate information you get from the news. Also, if you carry it regularly, annotate it with any information you find useful or interesting. I draw some maps into my notebook which has the advantage of fixing the information in my mind, but a cut and folded gas station map, a page from an atlas, or an internet map or two could all fit the bill depending on the area.