Great info - Thanks! I'm leaving for Turkey in a couple of weeks. I will be in Istanbul and visiting small towns on the south-west coast near Marmaris. Can you give me a few more details regarding carriers and cost? Would I have any difficulty in purchasing a plan as a non-Turkish resident?
Great! I'm currently in Ankara, but I can truly say that Istanbul is a magical city. Enjoy your time over there. And don't forget to take pictures for friends.
There are 3 carriers available in Turkey right now, all GSM and has good 3G services. Most popular one and the most reliable one is Turkcell(with market share over 50%), followed by Vodafone, which is cheaper but not as reliable as the first one. I'm using a Turkcell data plan with 4 gb limit, costs around $30 with all the tax included. They don't have any pre-paid data plans .I was able to get a commitment free service with some help from a colleague. Turkcell is the best one here, with excellent coverage and fast speeds. Far better than At&T for comparison. They require passport from foreigners and $20 one time only service fee. Prices are like 1 gb for $20, 4gbfor $30 and 8gb for $40.
Vodafone might be a better alternative for you as they have actual pre-paid data plans. Their 3G coverage is not as good as Turkcell, and sometimes 2G only in rural areas. Pricing is a bit different, 1 gb for $8, 5 gb for $30. They have plans such as hourly, daily or weekly unlimited. However, you may need to send a text message in order to activate these, I don't exactly know.
Third carrier is called something like Ave, and I have no idea about their prices. What I've heard is their 3G is the worst.