Bought my wife a folding bike Strida SX, but I suspect that I will have to ride myself. I tried it for the first time today, drove kilometers 20 about. At first it was difficult to get used to the fidgety steering wheel, too free to move, but it turned out to be a matter of time. Very comfortable design — you sit as if on a stool and almost no effort is needed to the pedals, the impression is that they themselves are spinning.
Well, it folds up in a couple of seconds and turns into a conveniently portable object weighing 10 Kg. Or you can just roll it in front of you. 
