the strida invisiblehand mentioned is a very capable bike because i actually rode 60km with that on one sitting with a upgraded sprung seat. it does take up very little space if you are standing with it and lock the brakes with their neat little locking mechanism. The gearing in the low 50's is good for minor hills and a slow cruise. Seems like the same price as a carryme at this US store at $650:
Folding Bikes: Greater Versatility = More Bicycling Opportunities
FWIW ... $576 at lickbike.
Lickbike.com | Strida LT Folding Bike 5.0 2015