There's one in the city an hour from where I live, but I've never been there. It's right next to the waterpark, so sometimes in the summer, they have special nights at the waterpark so you can come and swim and play and then finish the night up watching a movie from the lawn. There also used to be one about 8 miles away,outside of the town I grocery shop in, but it was closed my whole childhood and burned down when I was a teenager. Now there's no sign it was ever even there.
there are a couple within a 30 minute drive from me, but they're owned by the same people so they generally show the same movies. the drive in is great. $11/person for 2 movies, and you get to sit in your car (or in chairs in front of the car) and smoke weed all night. on tuesdays it's $5/person, and thursdays are $15 carloads. pretty sweet.
There are two drive ins here. But they aren't used regularly, only for festivals and events. They play the Big Lebowski on one of them every year.
http://www.dependabledrivein.com/ this one is pretty cool, Ive been there a few times.. not far from me..