Hello
I believe the book you are looking for is There's No Place Like Here by Cecelia Ahern. The author is the daughter of Irish Prime Minister Bertie Ahern. Cecelia Ahern has published four novels including P. S. I love you which is the basis for the movie starring Hilary Swenk.
For a bio of Cecelia please see: http://www.nypost.com/seven/11182007/tv/lucky_charm_715181.htm?page=0
Here's what Amazon says about There's No Place Like Here:
Starred Review* Ahern's inventive fourth novel lays open the life of Sandy Shortt, who has been obsessed with missing things and people since her childhood, when her nemesis, the blond and perfect Jenny-May Butler, disappeared. At 34, Sandy tracks missing people for a living. When she's hired by Jack Ruttle to find his younger brother, who disappeared after a night out with his friends, Sandy travels to Limerick to meet her new client. The two cross paths at a gas station, but before their arranged meeting, Sandy goes on a jog and finds herself far, far off the beaten path in a land filled with people and things who went missing from all over the world. Unable to find their way home, the missing have formed their own community, which they show to the thunderstruck Sandy. And Sandy, who has always remained remote from those she should be closest to, discovers that finding the missing people and things she's spent her life looking for doesn't make up for all the things she's been missing out on in her own life. A positively magical novel, Ahern's latest sparkles with wit, compelling characters, and a truly clever premise. Huntley, Kristine
Ahern's two other novels include If you could see me now (2006) and Rosie Dunne (2005)
