I posted a few pics with my synthetic snow. I bought the stuff from Woodland Scenics that model railroaders use, and sprinkled that onto a board. It looks amazingly authentic and it's nice because you can get into vehicle treads, create footprints, etc. Sets you back about $8 for a giant bottle that's plenty big to cover a 5' x 5' area or so, with plenty left for heaping onto vehicles or what not. It's also a dry powder so it's completely reusable if you're careful to capture it all
Check it out in these photos:
Ice Vipers
Cold Front