A tray of dry used coffee grounds (for a project I was going to do), and a small box of all the plastic animals that we have accrued in the past 6.5 years, and a muffin tin. This, surprisingly, is fun.
Then, when you want just one more cup of coffee/moment of quiet, give the toddler a warm, soapy bowl of water on a towel and have them wash off the animals. This, is even more fun.
The only mishap is when my babe took a spoonful of coffee and tried to eat it when I first put it in front of her. Yep--I'm the parent of the year!