I've been thinking about getting a foldy since I started using METRA to get out to the suburbs for work projects. Although its Bikes on Trains Program permits regular bikes, there are a number of restrictions:
[It] is designed to enable cyclists to bring their standard-form bicycles on board trains during weekday off-peak hours and on weekends. Three bicycles are allowed in the priority seating area in each accessible diesel rail car; two in each electric railcar.Also, whether bikes are allowed on or not is up to the discretion of each conductor despite the program. So it would be easier to have a foldy in a bag that is simply considered baggage.
My research has turned up two elegant, lightweight models. The more traditional of the two, The A Bike, is the creation of Daka Design in Hong Kong.
[It] breaks new ground in the areas of weight, folded size and design. Weighing in at just 5.5 kg, this ultra-portable folding bicycle is the lightest in its class. By utilizing quick release clamps, fold and unfold only takes 10 seconds...
It can be easily carried on public transportation network, and its compact size allows for easy storage. The A-bike can attain normal speeds without having to pedal any faster than with an average large wheel bike...
The second, by Thomas J. Owen in the UK, is The One. It's
a comfortable stylish bicycle that not only offers all the benefits of cycling (like cheap travel and exercise) but with its revolutionary power assist system the user can cruise around with ease. When folded, ‘One’ turns into a smooth, light and compact case free of all dirty and protruding parts.
‘One’ can be easily carried, stowed and stored. ‘One’ is truly a bike for eco and money minded individuals alike. Its stylish design strips it from the folding bike stigma and makes it a bike for the 21st century.