Intended at first for kids out of school for summer, but you could probably divert anyone with this.  Bella and I tried our hands at homemade ice cream this evening.  We made vanilla-Heath “blizzards,” and they were great.  Best part?  Took 5 minutes, start to finish.  More details are over here, but the basics are just milk, vanilla, and sugar in a zip bag, shaken for a few minutes (4, for us) inside a larger bag containing ice and rock salt.  Try it!  If nothing else, it will distract you from HARRY POTTER for five minutes.  Sheesh.