Edited to add: My Hive Overmind compatriots at Cosmic Variance have more details.]
Hey, is the Earth still here? Because the Large Hadron Collider saw its first proton collisions today!
OK, it wasn't at full power, and this is just a preliminary test, but still: It works!
In the graphic above (click to get the whole thing, plus others) shows the particles detected in the ATLAS experiment, one of the two big detectors on the LHC. The paths of the particles are shown, and they all trace back to one spot (or close enough), indicating they all emerged from the same patch of space inside the collider, just as you'd expect if they were the products of a subatomic collision.
There's still a long way to go, but this was a very important step along the way. Congrats to everyone at CERN!