I was idly watching Food Network last night and stopped to watch the show that was on.  It was all about ice cream, in addition to talking about commercially made ice cream, they even talked about homemade ice cream.  They showed this ice cream maker that is perfect for camping trips, and picnics, something you could take along and without any electricity, make your own ice cream.
camping cookware
When I saw this, it reminded me that it would be a great addition to camping cookware, especially families that have campers and go on road trips.  It's called the Play and Freeze ice cream maker.  It's a plastic ball that has a metal core in it.  You put the ice cream ingredients in one end, and the ice and rock salt in the other.  Watching them play with this, making ice cream, I was reminded of how cool it would be to have this new kind of camping cookware.  Once you have it filled, and secured both ends, you simply shake it up.  This might be the only time you could make a game out of camping cookware.  Roll the ball between two people, or even play catch with it.  When was the last time you did that with other camping cookware?  In no time you have home made ice cream.

I haven't used this myself, but I have seen the coffee can method used and it really does work.  After all, this is more of a streamlined version of those bigger, electrical units you have at home.