Here's another question, the Large Hadron Collider at CERN. It's one of the biggest international science projects in history, the engineering and logistics of the data collection alone are incredible, let alone the particle accelerator itself. It may support, create or disqualify any number of physical theories (or it may add very little to our knowledge

). It is not due online till 2007 (i think?) but if it was, would it deserve a place in the 'Modern Wonders'?