Space weather, for Jason.

"Navigation, power and communications systems that rely on GPS satellite navigation will be disrupted by violent solar activity in 2011, research shows.

A study reveals Global Positioning System receivers to be unexpectedly vulnerable to bursts of radio noise produced by solar flares, created by explosions in the Sun's atmosphere.

When solar activity peaks in 2011 and 2012, it could cause widespread disruption to aircraft navigation and emergency location systems that rely heavily on satellite navigation data." LINK

While 2012 is the blah blah blah "end of time" for the Mayans, and in that St. Malachy Pope Prophesy thing, solar flare cycles are picking up already.

"(12/18/06) - A large electromagnetic "storm" has broken out on the face of the sun, sending masses of charged subatomic particles through the space that surrounds planet Earth."

"Astronauts scampered to shielded areas of the international space station and space shuttle Discovery Tuesday night to protect themselves from possibly being exposed to high levels of radiation from an unusually large solar flare, NASA said." LINK