Just getting on with business in Amsterdam.
Joanna and Marc-Peter use their Workcycles Cargobike for both kid and cargo hauling. They're the Dutch distributors of the Micro kick scooters and balance bikes we love so much (and sell). Their record is apparently 30 or so boxed scooters on the Cargobike.
As of October 2014 WorkCycles has replaced the Cargobike with the lighter, even better riding, handier Kr8: