If the Zigo wasn't quite up your alley, here's a take two for you. The Taga stroller is a foldable bike/stroller hybrid that allows you to take a spin through the park while getting two of your children out for some fresh air. No more arduous walks battling rotating stroller wheels that just don't want to point forward, you'll have an enjoyable bike ride and give your children an early love for outdoor recreation without a large, awkward trailer shadowing your every move.
The best part about the Taga is it is quite customizeable. Add rain covers to the child seats for a quick ride when clouds are looming, use baskets to haul around less valuable merchandise and adjust the length as needed to fit your load. They even have a bassinet attachment for the youngest riders. When you reach a destination where bikes need not apply, quickly transform the Taga into a regular stroller and push your children around--even while your child is sleeping soundly in the seat. The foldable design allows you to easily slide the bike into your trunk and take it on the road.
While putting the children on the front end of the bike might seem rather hazardous to some, if your biking skills are such that you risk running head-on into a brick wall, then you should probably stay off of the bike with or without children. On the plus side, transporting your children on the front end allows you to easily monitor them and talk to them without having to turn around and yell into the wind. Plus it makes it impossible to turn your head at mile 10 only to realize that your child is somewhere between mile 7 and 8. They'll never leave your sight, so you can breathe easy, at least for the half hour that you're on the bike. After that, it's every boy and girl for him/herself.
So far no mention of a US distributor, but a variety of European distributors are taking orders.
Taga via DVICE