Lust: or No Harm Done - Geoff Ryman I probably wouldn't have picked this up by its own description, but I loved Air so much i'll basically give anything by Ryman a shot, and in this instance, i'm glad I did.

Michael, a gay London scientist, gains a sudden ability to materialize copies of people - alive, dead, fictional - that he wants to have sex with. When he wants them to, they vanish back into the ether, no consequences.

Remarkably, Ryman manages to spin this out into an entire novel without it getting stale. Even more unusually, to my reading habits at least, is that the stakes always stay firmly on Michael - the only thing in the balance of the entire book is whether Michael will be happier or more miserable at the end.