german scientists have taken the idea behind insulation used in many european homes to create a mug that will help keep drinks at the optimal temperature for longer periods (20-30 minutes, under "ideal conditions"). the mug is lined with a phase change material ("PCM") that is similar to wax. it melts at a certain temperature point (depending on the vessel's use - 136 degrees for coffee/tea, 47 degrees for beer, etc) and slowly releases that stored heat to keep the liquid at the specific temperature. i don't normally take longer than 20-30 minutes to drink a cup of coffee or tea, and i don't really care about keeping other drinks colder than room temperature (especially not for longer than 20-30 minutes), so while i think the science behind this is really cool (har), i'm not necessarily going to run out and get one of these mugs (if and when they're being manufactured). i do, however, think the same idea in a plate or bowl could be very useful - keeping soups or entrees consistently warm (or ice cream, cold) could be really helpful at home AND at restaurants. (think ruth's chris steakhouse's 500 degree plates.)
you'd just have to make sure not to use the ice cream smartbowl for your veggie soup or vice versa.
[image: fraunhofer institute for building physics]