Things I've learned [longer version, installment one(ish)]

If you're female and traveling to Turkey, you've probably heard one (or both) of these things:
"Turkish guys are so attentive (cute, too).  They'll help you get anywhere, and they're really friendly."
OR
"Turkish guys are creepy.  Avoid them like the plague."

Here's the deal: yes, some Turkish guys can be creepy as hell.  But so can American guys.  (Personally, I'm thinking frat boys, but I have some friends in fraternities, and they're not creepy.  See?  Stereotypes in action.)
But in the end, you do need to know what you're going to deal with (especially if you're traveling alone, and are young.  Or blonde).
It doesn't matter how conservatively you dress.  My worst experience occurred when I was showing less skin than I typically do at church.  Undoubtably, somewhere in the city, there's a local girl who's dressed less conservatively than you are.
But you're still American (or potentially European, or Canadian), and therefore loose (American and European girls just about as desperate for sex as the other, and, well, if you're Canadian...I'm sorry, but you know the routine; you may as well be from the states).

Guys will be attentive.  They will call you all sorts of endearments, some of which you wish you'd only be called by your significant other and not some strange guy ("angel" is great from your father or boyfriend/husband, but, uh, not some random guy selling tiles at the Grand Bazaar).

If you want to flirt, go ahead.  It should be fun.
But if you don't want to flirt (like me), grow a backbone, and fast.  I don't mean that you don't already have one, but if something you say can potentially be taken in a romantic/sexual/anything that's not "get the hell away from me" way, it will be.  They will read more into it, often, than you mean, and if you're not used to the attention (like me), it goes to your head faster than 90 proof alcohol goes to the head of a 15-year-old, and things start to spin out of control.  And I can pretty much guarantee that it will suck.

On the other hand, not all Turkish guys are like that.  Most are nice (often nicer than Americans), but just want to say "hi," or make you smile, or get to know you (this is especially true if you're studying here and they want to be friendly, not creepy).
Unfortunately, the guys who come on strong typically hang out around (or work at) the stretch between the Grand Bazaar and the Ayasofya--in other words, the touristy areas.  On the upside, it's damn easy to get directions from them, if you can figure out how to peel them off your arm later.

m.