Istanbul and Warsaw travel advice?

Okay, so next week will be a whirlwind for me... speaking at two Word of Mouth Marketing conferences -- one in Istanbul, and one in Warsaw.  Anyone got travel advice for either place?

I'll be in Istanbul 3 days, and Warsaw 3 days, so not a lot of time, but... would love to hear anyone's advice on things to see, things not to miss, etc.

Oh, and since this post wouldn't really be a proper DK post without some political content... I'm going to be there from May 3rd to May 9th.  I'm excited about it, of course, but slightly bummed that I will be overseas... when Hillary drops out on May 8th.