People Working for God

I don't know about at your house, but here's what half the shelf behind my toilet looks like:

My kids LOVE bath paint. Mostly, they just smear it all over the walls, but that's okay, too. If you look at this stash closely, you'll see THREE bottles of purple. My daughter's favorite color has been purple pretty much from the day she was old enough to declare a favorite. Until just recently we were out. Let me tell you how we ended up with such a stash.
A few weeks ago, my husband and I enjoyed a rare evening away, attending a party at some friends' house. The sweet lady who babysat my children was there from dinner through bedtime so she got to experience the joy of bath paint as well evening prayers. That evening, my daughter prayed that God would bring her more purple bath paint since she was out. A few days later, that same lady happened to be walking through Walmart's Christmas section and stumbled across a stash of bottles for $1. I had already shopped for some more for my son to give his sister on her birthday. Needless to say, God answered her prayer.
It just struck me how for something so little, and so unimportant in the overall scheme of things, He made it quite obvious that He was working in our lives. I didn't even know about the prayer until after she had received all the bottles. But God did. And he used our friend to answer it. How cool is that? Ever wonder if God is using you for anything, big or small? Have any experiences where you know for sure He did?