As an non-American I am intrigued by the modus operandi of current elections!!

That is why you are told not to fully believe everything you read from the media or heard from media Projection, sometime they also make mistake, as shown in the past Florida 'hanging chad' lampoon. But once a candidate got more than 270 electorate college votes from across the land, it doesn't matter a state like Florida is still counting the vote and if Mr.Mitt Romney is declared winner later, mathematically he is still below the minimum threhold require to win in this presidential election even though he carry that state after Floridians finally complete their count week or month later.

The presidential race is decided by electoral votes. These are votes that each state has depending on their population. To become president a candidate must have 270 electoral votes. Obama got 279, and there was no way, mathmatically, Romney could get enough, so that was that.

In the US, election officials tend to release the latest data whilst counting is going on, sometimes they do this on a 15 minutes basis. Therefore, once the polls close and the counting begins, the TV stations show the updates, with 10%, 20%, 50%, 90% of precints reporting, etc. If the gap between two candidates is large enough, the TV station will 'call' a state for a particular candidate. However, if the gap is very small, the TV station will say 'too close to call', as they have learnt from their mistakes back in 2000 when they wrongly called Florida for Gore on the results of early counts, only to find as counting continued, that it became too close to call and then ended up with Bush leading, etc.