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.
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.