We built the pyramids. We sent a man to the moon. We even figured out how to get internet access on an airplane. And yet — someone STILL has not figured out how to design decent sippy cup for kids! While I am thankful every day that my girls drink out of a cup, the wounds are still fresh from those days of searching for the pieces to put one back together after running it through the wash — not to mention the never ending stench of rotting milk trapped in the straws, and the clutter in the cabinet of mismatched tops and bottoms. I have tried MANY over the years and have never really been that happy with any of them. For a long time the front-runner was the sleek looking Sigg which was durable and only TWO pieces — but I found them to be too small and tough to open. And now, although we are not quite there, the recently discovered CamelBak is the best one to date. It is very kid-friendly, BPA free, does not leak, and is easy to clean (although three pieces.) It holds up great after a lot of abuse and it is a nice size. They also have great ones for adults and are available all over the web and at Whole Foods.