Oh MY GOD! I <3 the food pics and Turkey! Gosh another country to visit on my (future...) trip to Europe (I'm just a poor student for now.)
The lack of SIM problem in Turkey can happen in any country. What happened is your mobile phone's IMEI# is on the Turkish providers black-list for some reason. Most likely what happened is that their billing system noticed that from previous SIM/subscriber/session you either didn't pay your bill on-time and you have monetary settlements or something else. Since you're going back to Turkey with students in the future you should definitely take care of this with the provider. Sometimes you can even pay off the bill with a CC using a web-app after giving the SIM associated # or IMEI#. If not contact their CS.
The Tokyo pics are lovely too. I'm from Asia originally and have been dying to get back there sometime in the future. Well I'm still young and student so reading FT will make me dream for now.
BTW what do you lecture/teach?