Someone gave me Meg Cabot's The Mediator books 1 & 2 (Love You To Death & High Stakes) this past Christmas.
The story centers around a young girl who communicates with ghosts, much like M Night Shyamalan's movie The Sixth Sense. Only this time, it's written with humour, a ghostly love interest and a very brave yet brash heroine. Can't wait to get my hands on books 3 to 6 as books 1 & 2 were delightful to read with it's vivid imagery, I can easily imagine this as a popular TV series or even movie. It's written for teens to young adults and just the sort of paperback adults pick up at the airport.