The Carryme is much more solid and a waaay better ride than the Abike but then with the carryme it is alot heavier and you will not be able to put it into your backpack. It doesn't fold anywhere as small as the Abike. The abike is really the smallest we have here, and it comes with it's own backpack also for you to put it in. 1-2km would be ok and it should be much more stable than roller blades. At least with a bike you can ditch when in trouble, while roller blades are stuck to your feet if you are not good at it and really need to bail. Plus they also came out with an official Abike city which does come with 8 inch wheels now which is the same size wheels as the carryme.

This seems to be an official site but it's not a cheap bike though:

http://www.a-bike.co.uk/store/checkout1.php