The Time Traveler's Wife

By Audrey Niffenegger (although I think that Traveller should be spelt with two Ls).

A very unusual book but well worth a read. It's a love story, so I found it a bit wet in places, but the only way I can do credit to the book is to copy out the inside cover description:

"This extraordinary, magical first novel is the story of Clare, a beautiful art student, and Henry, a librarian, who have known each other since Clare was six and Henry was 36, and were married when Clare was 21 and Henry 30. Impossible but true, because Henry is one of the first people diagnosed with Chrono-Displacement Disorder; periodically his genetic clock resets and he finds himself misplaced in time, pulled to moments of emotional gravity in his life, past and future. His disappearances are spontaneous, his experiences unpredictable, alternately harrowing and amusing.

"The Time Traveler's Wife depicts the effects of time travel on Henry and Clare's marriage and their passionate love for each other as the story unfolds from both points of view. Clare and Henry attempt to live normal lives, pursuing familiar goals - steady jobs, good friends, children of their own. All of this is threatened by something they can neither prevent nor control, making their story intensely moving and entirely unforgettable."

If you thought "there are no new love stories" then you truly should read The Time Traveler's Wife.