It appears solar sailing is finally making the change from blue-sky speculation to a working technology. The idea isn't new, of course -- the theory dates back to the Russian physicist Pyotr Lebedev before the First World War. In the early 1960s solar sails were all over science fiction stories for a time, and I suspect many of the scientists and engineers working on real-life sail projects got their first exposure to the idea from stories by Arthur C. Clarke or Jack Vance.
The Japanese space agency has scored the first major success with their IKAROS project (bonus points for a nifty acronym), which is going through in orbit before trucking off to Venus.
After a failed start, NASA is getting back in the game with the Nanosail-D project, a small-scale solar sail designed to test how you deploy and control something big and flimsy in space.
It all brings to mind Tennyson's poem "Locksley Hall," in which the narrator has a vision of the future and
"Saw the heavens fill with commerce, argosies of magic sails, Pilots of the purple twilight dropping down with costly bales . . . "