I know a few people who say this all the time and now theres a mug for it too!
 
Printed on an 11oz ceramic white mug with a standard curved grip handle.  This design is also available on a black colour changing mug.  Both are microwave safe and even dishwasher safe too!  It's printed with fade resistant long lasting inks that won't scratch.
 
Posted to you in a smashproof box which means less packaging and less waste too!