I know what you need. A Burro (or Burrito) with SS couplers. It doesn't fold, it breaks apart for packing, but that should be ok because if you were looking for a hurried solution then you wouldn't be hiking to begin with.

http://www.sandsmachine.com/bp_buro.htm
http://www.burrobikes.com/


A little pricey though. Maybe you can get a similar result by adding SS couplers to a BMX bike?