Facebook has just launched (literally just – you can see how few votes got counted on the screenshot, it’s now up in the hundreds) an appplication that tracks US voting for today’s presidential election in real time – just as polls open on the East Coast, including key battleground states in Ohio, Virginia, Florida, North Carolina and New Hampshire.

According to Facebook, the dynamically updating map is based on “people who clicked on an Election Day prompt to share with their friends that they’re voting in the 2012 US election”. The information displayed has been anonymised.

The map displays bursts of activity as people share that they’re voting. The size of each burst matches the number of people voting in that region right now. The histogram shows a record of activity over time, with an additional breakdown by gender and age.

It should be a great way to watch the progress of votes through the day. And for political data nerds, it will be the icing on a well-baked cake of Facebook’s importance in the 2012 cycle. Both the Obama and Romney campaigns have relied heavily on Facebook Platform integrations as well as ads across the cycle and tonight we’ll know who’s social media mojo helped carry them to victory.

Check out the progress through the day at Facebookstories.com/vote.

UPDATE 1230 GMT: As more data flows in we can now see what they mean by the bursts of activity. Of course, if you’re wondering why you can see bursts of activity in states where polls aren’t open yet, it’s likely down to people registering their intent to vote or their already having early voted. (In Nevada, something like 70% of votershave already cast their ballots, for example).