Free Prometheus t-shirt

Well, I'm getting the poster tonight and it looks like I'll be going to the first showing at a Cinemark theatre tomorrow morning. Is there a link for participating theatres like Imax has? I had bought tickets to a certain IMAX then had to get a refund and purchase at a participating theatre to get the poster. Not making that mistake again. Where did you see this?

I looked it up and there isn't a list. I'll have to call. Also, take notice, the ad seems to say that you'll get a shirt if you see it in RealD or XD but it states they're only for XD ticket holders.