Wormholes? Maybe.
A number of people have e-mailed with the BBC's coverage of the some "new theories" from a Russian scientist that have been unveiled in New Scientist magazine. The theories have been met with some skepticism by the scientific community, so don't go planning your vacation to Alpha Centauri quite yet.
The original New Scientist article is online, as is the full paper which has much more content.
This is interesting, but even if it turns out that they can be found (or built), there may be problems. If they can be moved, you can turn one into a time machine (giving causality the finger) by accelerating one end to relativistic speeds and taking it on a trip, as noted in the actual paper (but ignored by both the New Scientist and BBC articles).
A reasonable SF treatment of this particular idea is in Robert Forward's Timemaster. The characters make cardboard look 3D, and the prose isn't the most beautiful, but the main hook is the physics speculation--and Forward does that quite well.