Sippy cup problem

So, over the course of several years and a few children, I have accumulated an array of sippy cups. You see, different kids prefer different types. Sometimes you buys some hoping that they really will be leak proof, but they aren't. As time passes, parts get lost at the park or to putrid milk or the black hole of the diaper bag.
And more often than not, your child is cranky and/or hungry and just wants some milk. And you are faced with this:

Hard to find a lid to match the bottle and a valve to match the lid. Utter madness!

So, I bought these as a gift to my sanity. Interchangeable. Enough, but not so many I can't keep track of them. And as about as leak proof as any brand can manage!

It's the little things in life, really.