If your old ‘convince the grandkids to sit here and crank this handle for three hours’ bucket-style ice cream maker breaks down and you don’t wanna spring for a newfangled electric model, you might be interested in this yo-yo, called the Urawaza Spin Ice. I’m not sure how it stays below freezing, but the up-and-down, er, yo-ing of the yo-yo performs the cumbersome manual labor of constant stirring which gives ice cream its velvety texture (as opposed to the non-stirred variety known as “unappetizing block of ice”). Presumably due to the small quantity of cream in question, the whole process takes a mere ten minutes (as opposed to 30+ minutes for even electric makers) before you’re licking creamy goodness off your lips. Looks like these are only available in Japan for the moment, for around $15.
NTV Service’s Human-Powered Yo-Yo Ice Cream Maker [TreeHugger]