There are lots of travel mugs that promise to keep your drink hot or cold for hours, but they only work if you have them with you. The Auto Hot or Cold Cup Holder at Sharper Image is safe for any 12-20 ounce paper, foam, or plastic disposable cup and metal cans; images at Sharper Image also show it being used with a disposable plastic water bottle. The holder plugs into the car’s 12V DC power outlet (can’t be used with home power outlets) and keeps your beverage at a “stabilized” temperature. It has a power switch, or it will turn off automatically 10 minutes after the cup has been removed. The Auto Hot or Cold Cup Holder is $39.99.