Meet LAVACLIP: a portable, rechargeable coffee warmer that attaches to the bottom of your cup and keep your coffee warm. Its heater comes in direct contact with the bottom surface of the cup. You can charge LAVACLIP using any standard USB outlet.
LAVACLIP keeps your coffee warm at the proper temperature for about one hour on a full charge. It will be compatible with standard car cup holders. More info is available on Kickstarter.