How about carrying a cigar or two? That might keep people from assuming too much when you have a lighter and nothing to light.

I think you have a good start with what you mentioned; you might want to put a small whistle on your keychain, like a Fox 40 mini.

A small Swiss Army knife would be a good addition if you can't carry much else in the way of knives or tools. (Maybe even a Leatherman if you can swing it.)

Last but not least, a pre-paid phone card comes in handy when the cell phone networks don't work or are overloaded.