Beverage Can Turned Into It's Own Cup
You could have a pull tab that removes the entire lid of a beverage can with one pull and have the sides perfectly round and safe for drinking from eliminating the use of a cup and helping reduce that dribble down your chin from the small hole in an average beverage can. It would in effect turn the can into a cup where you could add ice or any other ingredient or you could freeze the can for long term storage and dump it into a cup (very fast) or make a great tasting slushy type drink by blending it. Just try and get a frozen beverage out of a small hole in the standard top of a can!
And when you're really thirsty you could really chug any liquid out of this kind of can; no air restrictions!
Reward: Too be able to place ice in a can of pop without dirtying a single cup rather than doing the dishes all the time!