Sent by RichardEditor: Richard, this is a great question and something we were just wondering about too. But we can't think of much besides the aforementioned blender and the food processor. One idea, too, if you already have an ice cream machine, is to start from scratch and just put water in your ice cream machine and let it run. It would probably turn into a sorbet-like consistency, somewhat similar to shaved ice.
Readers, any other ideas?