Lust, or No harm done - Geoff Ryman

What if you could sleep with anyone in the world, just by thinking about it?

Michael Blasco, a young scientist, is waiting for the train when he spies a friend he fancies. Idly, he imagines Tony naked and an extraordinary thing happens - Tony strips there and then on the platform and offers himself in front of all onlookers. Horrified, Michael flees. But back home, Tony magically reappears. Then disappears, when Michael wishes him away.

Michael sets out to test the parameters of his new-found gift, rapidly calling up Billie Holiday, Johnny Weismuller, Lawrence of Arabia, Alexander the Great, Picassao, and even his younger self. The world is there for the taking and Michael runs the gamut of his fantasies. But what does he really want?