Get a money belt. Not sure if that's what it will be called on the package, but what I'm talking about is a flat pouch you wear around your waist under your clothes. Good way to carry passport, traveler's checks and anything else important while traveling abroad.
Reaper is correct about currency exchange. Also bring traveler's checks instead of cash. Exchange minimal amounts in each country and use credit cards whenever possible.
I had no problems drinking the water when I was in Europe (although this was long ago). It ain't Bangladesh.
