A friend and I were on a trip to Lynchburg, Virginia recently, when one of our friends got us free tickets to a year round ski and snowboard mountain called the Liberty Mountain Snowflex Centre. The "mountain" is made of a synthetic material that looks and feels like rigid carpet, developed in the UK by Briton Engineering Developments that allows riders to hone their skiing and snowboarding skills in and out of season. We were both skeptical as to how "carpet boarding" would treat us, but the results were an unexpectedly fun night of riding.
Liberty University is a non-profit institution kind enough to spend some extra funds on this little slice of imitation-wintery fun. The general public can enjoy the mountain for about $5-7 (per hour) for admission, and $12 equipment rentals. The mountain itself is short, but littered with enough jumps, jibs, rails and whale tails to keep you entertained for hours. My personal favorite was the bomb drop into their jump section, with a sizable quarter pipe at the end. They even had a jump into a giant inflatable, but sadly it wasn't in use while we were there.
If you can't wait until winter, I'd suggest dusting off the boards on your and heading for your nearest Snowflex mountain (find a list of locations here). It's no Breckenridge, but it'll do until winter blesses us with its first snow.