Urawaza Spin Ice looks and works like a yo-yo, but there's a small container inside which makes ice cream as you spin the toy-like device. It's basically a tiny miniature of the inexpensive home machines that use an insulated freezer bowl and a crank to make mushy but delish home-made ice cream. You put cream, sugar, and whatever flavorings you like into the container, insert it into the yo-yo, and after about ten minutes of spinning, you should have something at least semi-solid to eat.
Needless to say, I want one. It's only out in Japan right now, for about $15.
From Nikkei.net.