While I was surfing Internet today, I found a very cool gadget: On/Off Mug. It is a good idea to gift someone this On/Off Mug.
When the mug is full of hot liquid the cup turns white and is emblazoned with the word ON in black letters, and as it cools down it turns black and clearly screams OFF in white letters.
Features of On/Off Mug:
A funky heat-sensitive mug.
When the mug is empty or filled with a cold drink, the mug is black with a large 'OFF' emblazoned on it.
When the mug is filled with a hot brew, the mug becomes white with a large 'ON' emblazoned on it.
This product is not dishwasher safe. Handwash only.
Suitable for ages 12 years+.
Size: 9.5 x 11.5 x 8cm.
The price of On/Off Mug is aprox. $25.55 and it is available at http://www.iwantoneofthose.com/new-arrivals/on-off-mug/index.html