I've already responded to PB's post about third places, which are places where adults can go to hang out without buying much. (Compared to my average night out with Jennifer Beautiful, say, which includes dinner, a movie and pedicures, with a price tag of something like sixty bucks.)
I wrote a response on her blog already, but her post is still nagging at me. I'm realizing that as I think about it, I used to hang around "third spaces" all the time.
I was at the mall (not buying most of the time) or at a teen club in my town most nights of my teenage years.
Remember that episode of Buffy where the adults all become irresponsible teens? The first thing they do is start "hanging out" on the streets.
As an adult, I have friends over for dinner and I call my friends a lot, but I don't hang out much. Probably the closest thing I have to a non-consumerist hangout spot is this blog. (Though I do have friends who frequent this one neighborhood bar and know all the regulars.)
Perhaps we've developed a cultural thing against hanging out and sort of collectively decided it's a teenage thing.