We recently purchased a weehoo for our 2 (almost 3 yo). He didn't like riding in a burley trailer anymore, he wanted to be riding and pedaling. He LOVES the weehoo. Attached to my bike is a burley piccolo for our 6 yo and attached to THAT is the weehoo. It's a very long train. I use it to take them to and from school/daycare and to soccer practice, the park, etc.

If I'm going to get groceries, I leave the kids at home and take the burley trailor.