Scientists at CERN have managed to trap 38 atoms of antihydrogen, marking the first time outside a Dan Brown novel that anti-atoms have actually been harnessed. And it only took 335 tries.
Antimatter is just like normal matter, except it's the exact opposite. If you get an atom of antimatter too close to an atom of regular matter (which are everywhere), they completely destroy each other and release an exciting amount of energy, about 100 times more than you'd get from nuclear fusion.
The first anti-atoms of antihydrogen were actually created several years ago, but since it doesn't have much of an electrical charge, the anti-atoms tend to wander off and annihilate themselves too quickly to be of any use. To get antihydrogen to stay put, researchers cooled it down to about one degree above absolute zero and used superconducting magnets to generate a teeny tiny magnetic field inside the anti-atoms, keeping them stationary for a few tenths of a second.
So why do we care about antimatter? Well, scientists have no idea whether or not antimatter obeys the same laws of physics as regular matter. It's supposed to, but nobody has been able to get enough of the stuff to sit still in one place to test it out. This new method of keeping antihydrogen around long enough to mess with means that we might be able to figure out whether it behaves the same way as regular hydrogen. If it doesn't, physics is gonna have some explaining to do.
Besides being a major plot point in Dan Brown's Angels and Demons, antihydrogen is one of the crucial components of Star Trek's warp drives, since combining antihydrogen with regular hydrogen is the most efficient way to produce energy that there is, period. Never mind that it currently takes 10 million antiprotons and 700 million positrons plus particle accelerator the size of San Francisco to make just 38 atoms of the stuff. Now that we've got some, warp drive is inevitable.