Originally Posted by Airhead Wrangler
Only down side is you can't keep a few sacs of dry ice laying around until you need it. It's probably not the cheapest option out there either.
The machine I saw in person was making it's pellets up on the spot from liquid stored in tanks. Some make snow the same way. You can keep blocks of dry ice a long time in a freezer---the grocery stores do it so they have it to sell.