We're not that into product endorsement. But this Strida collapsible bike is pretty cool, and we do claim to be an articulated mass of cyclists.
Areaware just started distributing them in the US, and the best part about it is that you can fold up the Strida bike and put it in the back of your Xtracycle bicycle.

That way you can bike to the train station to pick up your friend----and take them to the farmers market.
wonderful adventure tools.
love, sev.