We don't currently have any need for a wheelbarrow, but if we did, we'd probably consider this WheelEasy from Allsop Home & Garden. It seems like the perfect thing for an apartment gardener or a gardener without enough room to store a big, bulky traditional 'barrow.
The WheelEasy, which is made of canvas, collapses on the ground. So you don't have to lift anything into it, just rake, roll, or scoot whatever it is you need to move, then pick the thing up by the handles and roll it off, just like a traditional wheelbarrow.
Then, when you're done, it folds up for super-easy storage.