I've become obsessed with finding a use for these USB mug warmers. They cost less than a fiver and can get really hot. So many protocols we use in molecular biology require reliable heating to a specific temperature. Would love to turn one into a PCR machine. For the moment I'm using relay switches and DS18B20 temp sensors to make a hot plate that will remain at a user designated temp that you could use to grow a microbial culture, or incubate an enzymatic reaction, or loads of other things...