I'm thinking of spending a few days in Istanbul in August. Do I need any type of visa to get there?
Not in advance. You'll get your entry stamp from Passport Control when you arrive at the airport. Bring a $20 bill with you for this purpose.
The window for visas is separate from the Passport Control stations. Make sure you get your visa first. If not, the immigration folks will send you to the visa window and you'll have to stand in line at Passport Control all over again.
Hello!
It depends what kind of passport you have, what country you're a citizen of.
Good luck!