Mighty Mug Tip-Proof Drinkware
Here's something cool for the clumsy among us (yours truly included).
The Mighty Mug series of drinkware sports an awesome feature: Each one has a patented "Smartgrip" base that, once set down on almost any smooth, flat surface, creates a powerful airlock which prevents it from being tipped over if — who am I kidding, when — you accidentally bump into it. However, when you do need to take a sip, you can easily lift it straight up, no problem.
Watch their promo video to get an idea of what it can do:
They have a variety of vessels to choose from: