Hot plate stirrers: I got a used hot plate stirrer on e-bay a while back to try cooking with. Its intended purpose, dissolving things in liquid while warming them, makes it ideal for dissolving gelatin and agar agar. It also works well for reducing liquids that like to boil over (like cream until it gets too thick). I experimented with using it for sous vide along with a PID controller, but haven’t been entirely successful yet. I may just use the stirring element and an immersion heater attached to the PID controller. Overall I haven’t found it as useful as I originally thought (I don’t reduce that much cream), but don’t plan to get rid of it either.