“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.”

Looks like a great idea, though I think there is too many joints/parts to make it stable enough, after a few month of heavy use. Though if I had the space I would get one.

Link – http://www.treehugger.com/files/2007/11/a_couple_of_yea.php