Bit of a random one really but what do all those CC's out there do for phone contracts and keeping costs down whilst overseas?
I generally avoid using my mobile abroad - that's the easiest solution.
However, for those with iPhone I recommend the <Viber> app - it allows you to make local or international calls for free to other iPhone users that also have the app - it uses 3G or Wireless ... so if the hotel provides free wireless it can be a decent option.
Personally I just don't make voice calls overseas...