Until recently, I would have agreed with incitatus, but lately there have been major breakthroughs in this area of science. It has been found that Heisenberg's uncertainty principle can be 'compensated' for by using a technique known as quantum entanglement.
This method allows you to measure the exact state of atoms and dramatically lowers the energy that would be required. So far, scientists have transported photons, atoms, and even molecules of solid matter.
I'd imagine it would take centuries before humans would be 'transported' (and then there are the ethical debates), but science is increasing at an accelerating rate, and breakthroughs happen at the most unexpected times. We might discover a way to efficiently do this next week, or we may find something that disrupts this from ever being virtually possible.
So the answer is 'no', we cannot beam people up yet (unless the government is hiding something), but it seems just a matter of time before we find ways of transporting large bodies of matter such as ourselves.
More information can be found at:
http://www.newscientist.com/hottopics/quantum/quan
tum.jsp?id=ns99991888
(Then
again, I'm a trekker - I would say that... ;-)