This is real, the Airborne Laser, and it actually can shoot down missiles in their boost phase. The plan is to have 50-60 of these 747s operational in the next few years and to use the Test aircraft for war operations before that.
The critical invention of the "Rubber Mirror" for the Focusing beam was successfully tested in March 2001. It's over 400 small mirrors acting as one to create a focusing beam that allows the laser to cut through atmospheric distortions and maintain its power. The Flight tests this summer were all successful and I believe optics integration and shoot-down tests are next.
You can only shoot downwards from above, not effectively the other way around with this technology from what I understand. In addition the reflectivity of the surface of the missile might still be a problem, although the laser merely has to weaken the metal and the stress of flight takes the casing apart.
This is the BIG STICK that will likely revolutionize warfare and could make small-scale missile attacks impossible, according to "experts". Because they shoot 180 miles, the lasers can also be used to strike targets on the ground, burning a basketball size hole in anything (except maybe a mirror).
Imagine Bush, Cheney and Rumsfeld with a DRAFT.
Now imagine them with 50-60 Airborne 2 Mw Lasers. This is their plan for world domination.