In this this extraordinary article, The Scotsman reports that a hyperdrive engine could well be a possibility within 5 years. The engine is based on a fringe , untested area of physics, but the U.S. Airforce and NASA have expressed an interest.
"The hypothetical device, which has been outlined in principle but is based on a controversial theory about the fabric of the universe, could potentially allow a spacecraft to travel to Mars in three hours and journey to a star 11 light years away in just 80 days, according to a report in today's New Scientist magazine.
The theoretical engine works by creating an intense magnetic field that, according to ideas first developed by the late scientist Burkhard Heim in the 1950s, would produce a gravitational field and result in thrust for a spacecraft.
Also, if a large enough magnetic field was created, the craft would slip into a different dimension, where the speed of light is faster, allowing incredible speeds to be reached. Switching off the magnetic field would result in the engine reappearing in our current dimension"
The paper quoted in the article is here (Google Scholar, HTML version)
Full New Scientist article has been posted on LiveJournal here