Ebay:
Carinielli Graziella Folding Bicycle (vintage Italian)

I really can’t afford this, but I got it because I really could use a folding bike (and the price was pretty good). First, they would be fantastic for traveling (it was great renting a bicycle in Portland, but it is a pain having to use someone else’s bike and get used to it… and in lots of cities, there aren’t bikes to rent or if there are, they are too expensive), but secondly I want one to take on the OKC buses (at this time most do not have bike racks… I’ve heard this is changing, but my guess is that it still might be awhile) to expand my range.

For instance right now I normally drive if I want to see my parents in Newcastle (it’s 24 miles from my house to theirs, more than I want to ride on my bike, particularly since you have the return trip to make), but with the folding bike I can take the bus as far as SW 89th & Penn (I’m actually astonished that no buses run further SW than this), and then ride the rest of the way (13 miles, still a long ride but doable).

From what I can tell this model of a folding bike has quite a history in Italy. Here’s one article on them: Pagine70.com: Graziella, la bicicletta pieghevole (or as translated by Babelfish since I don’t speak Italian, “Graziella, the collapsible bicycle”>