A question for New Yorkers (and others)

There are at least two New Yorkers that read this blog (I have a very large audience ;). So I'd like to address a question to them.

You may have seen my two posts about the removal of zones on the new Tube map.

A quick bit of background: the London Underground network is divided into nine zones. If you know the zone you're in and the zone you're going to, you know how much you have to pay.

So, here's my question. I noticed that the New York Subway Map has no zones. How do you know how much you're going to pay for a subway journey? Or do you just buy a MetroCard and not worry about how much each journey costs?

Actually, this question could apply to anyone who lives in a city with an urban railway. Does your transport system have zones? If not, how do you know how much each journey will cost?