Norwegian Kroner (NOK), for some reason. Actually I have also a lot of Euro and other currencies in my wallet right now. I recently spent an extended weekend in Berlin, and haven't had the chance to exchange the leftover monet. I fly to Phoenix in three days, so I plan to exchange it all into USD at the airport when I leave.

Well, it looks like 1 Kroner equals about 17 cents in US currency, and 1 Euro is about 1.39 in US dollars. Since most pick-pockets are probably too dumb to try to do currency conversions, you're safe as well. <s>