Gekko ,helix ,A bike, loads of bikes from far east.......
Brompton is also only rollable on smooth surfaces. However it can be improved with larger wheels as can the flamingo and Merc.
Most rolling rack bikes can accept bigger wheels to improve this matter. I have rollerblade wheels on my Birides and mezzo. Mezzo can also be altered quite easily to a four wheel rolling folder. There are fitting in the frame that can be utilised if you can make or find the wheel holders. Ori do make them but easier to get from holland?