This first link is to A to B magazine's fine piece of journalism, entitled, "Why choose a folding bike?" 
Subsequent links are to a sampling of various manufacturers and purveyors of small wheel vehicles.

Why choose a folding bike?: http://www.atob.org.uk/folding-bikes/folding-bike-why-choose/
The entry-level proletarian selection: http://www.citizenbike.com/catalog.asp?product_category_id=1&product_id=1
Th American-made fastest folder: http://www.bikefriday.com/bicycles/commuter/1144
The bourgeoise selection of the erudite suburbanite: http://www.giant-bicycles.com/en-in/bikes/model/halfway/10774/53010/
The greatest folder ever (British): http://www.brompton.co.uk/
A small-wheel recumbent trike: http://www.catrike.com/catrike_road.html
The Duesenberg of small-wheels: http://www.moultonbicycles.co.uk/models/NSDoublePylon.html
The Duesenberg of small-wheel wheelchairs, the temporarily out-of-production iBOT ***: http://en.wikipedia.org/wiki/IBOT
Brompton Blog http://blog.brompton.co.uk/