1 Structural material of choice : Steel or Concrete?

Again, I came across another question as I probed my Strength of materials notes.

Steel or concrete?

I found a suitable answer here, which provides the benefits of each, and lets you do the choosing. Although I understood that steel has the highest strength to weight ratio and is very ductile, the recent events of 9/11 makes you question steel. Concrete on the other hand is an excellent fire proof material, which is sort of an intrinsic smartness that lowers costs.

But I wonder whats faster to build? A building made of concrete or steel? Maybe I'm not in touch with the development in concrete structures, but I always thought concrete took time to cure. Who would want to wait while it does that, especially when you have a million dollar construction contract? Hmm...whats that I hear? Pre fabrication?