These portals seem to be focused on places of intense creativity, points of emotional significance and areas vital to the public society. Research on both the portals and XM has created far more questions than answers; though some critical elements have become clear:

-XM has subtle mind-altering properties, and may have been involved in every major advancement and conflict throughout Human history.

-Unknown beings called The Shapers are the creators of portals and releasing XM to our world, guiding our development.

-An organization known as the Niantic Project is researching XM, and a researcher has leaked an application named Ingress that uses mobile phones to alter and interact with portals.

-Once the mind-controlling properties of XM were discovered, two factions with opposing ideals were created:

*The Enlightened believe that the Shapers are what has led us to the current advancement, and seek to embrace XM in order to let its influence lead us toward the next era of Human advencement. They alter Portals to produce more potent mind-altering XM that takes on a Green color.

*The Resistance believe that the Shapers are malevolent and seek to free humanity from XM's influence. They alter Portals to produce XM that counters the effects of Mind-altering XM, turning the portal Blue.

These Agents use their devices in the real world to 'Hack' portals to gain weapons and defenses to Claim portals for their faction.

Two portals belonging to the same faction can be Linked together by player visiting one of the two portals. If a third portal is linked together, forming a triangle, a Control Field is created within that triangle.

The larger the field is, the more Mind Units(MU) are inside it. (Which is affecting everyone within it to become more or less affected by XM)
The whole world is tallied up, and the side with the larger supply of MU is 'Winning' at any given time.

TL;DR Version:

Ingress is a game where you fight a turf war in the real world with your phone. Go to a park/Museum/Statue, break the opponent's defenses and put up your own. Level up for more powerful weapons and defenses, then create big fields for your faction.

I play on the Enlightened, because new things are AWESOME and I like the color Green much more than Blue.

It's Free to play, gets me off the sofa and there's a HUGE group of supporting people that organize on Google Hangouts to set up fun, coordinated operations together.

Anyone else play?

I'm part of 4 groups: A Newbie-chat for people with questions, one for the Northwest Chicago area, another smaller group for just my cluster of towns, and finally a group of 7 hardcore players that coordinate hitting larger areas and setting up large field plans.

The social part is what really hooked me, when a player asks if anyone's around to knock out an enemy portal near a train station that is blocking a massive field; it feels great to watch it melt and see an immense field of green pop up a minute later.