I'm lucky enough to live within about 1.5 hours of Bryce Resort (http://www.bryceresort.com/s-activities.html) here
in Virginia, which bills itself as the only resort in the US offering a grass skiing program. Apparently, Horst Locher, who is the director of skiing activities (or some similar title) brought grass skiing to the US from Austria in the 70's, and is still trying to keep it alive.
My girlfriend and I went about 3 times last year, and will definitely try to get out at least as many times next summer.
It's a lot of fun, and I saw serious improvement in my snow skiing as a result. I was an aspiring intermediate when I was on snow last season, but after spending time on grass skis, I'm gone a bit beyond "aspiring". I'm still not "good", mind you, but I'm better than I was. It really made me learn how to use my edges, since there's no skidding allowed.
I think Comprex has done it, too, since he's the one that turned me onto Bryce's program via the local DC ski forum.
What was really weird was when I was at Whitetail a few weeks back, and there was a guy on grass skis zipping over the snow. Strange!