There are few things more annoying than seeing your favourite mug wrapped up in the warm embrace of another person, which is why this idea is such a brilliant one. Never fear mug misuse again with this revolution in mug security - a small but rather vital hole in the side of this coffee cup renders the mug useless without its plug, which, with its handy key ring attachment, remains with you until your next tea break. Sheer Genius. Mind you don't lose the plug though, otherwise you may find that you're the mug.