A couple of years ago we suggested bicycling families might want to take a peek at the Danish trioBike. It is a sleek, modern rendering of the Dutch Bakfiets (here and here) with the added benefit of being modular. It is a carrier bike, that also converts into a bike and a two kid stroller. Now, emerging from the USA, we have the Zigo Leader, which, thanks to some clever design, takes the concept that little bit further forward.
The Zigo Leader also does a city bike (eight speed hub), three wheel carrier bike and a stroller, but ups the ante with the jogger option as well. (The trioBike might be able to do this too, but its plastic shell is no doubt heavier than the fabric utilised by the Zigo Leader.) The designers reckon you change to any mode in thirty seconds or less. And this might be the case, but claiming it as "the first mom or dad-powered family transportation vehicle" is just plain silly, as the above examples indicate.
You can see a slick, but rather disjointed, video of the bike in action, but it won't be on sale until after April 2008, when it starts to become available both in the USA and Canada. Some more info on the website, though it is very much a work in progress. :: SOMA Cycle