DucksNuts finds this interesting one at
Life Without Buildings, an architectural blog. The post there notes that there were 258 concrete trucks, each pouring approximately four loads, laying 11,500 yards of the stuff in one day. Look at all the trucks on the road, waiting for their turn.
What'll it be when it's all grown up?
Condos. Apparently this size of slab is needed to keep the building solid once it's up.