This Friday 15 February, 2012 DA14 will pass closer to the Earth than geosynchronous satellites. Per the NASA Impact Risk site, it's a zero on the Torino Scale (a combined index of probability that it will hit and damage if it does). Zero means there's no reason in wildest hell to think that it would hit us, or even if it did, it wouldn't reach the surface. It's a -5 on the Palermo Scale which is to say, 100,000 times less likely than a random background event.
If despite the careful work of modern astronomers, there's someone in your social circle who insists that this is the end the Mayans (or Christians, etc.) were talking about, ask them to give them all your worldly possession, and zany hijinx will ensue either way!