If you haven't seen it, you should. Here is a description:
"Clay Riddell is a disillusioned artist who a year earlier abandoned his wife Sharon and son Johnny in order to fulfill his dream of publishing a graphic novel. At Boston International Airport, Clay tries to board a flight, hoping to reconcile with his family. His cell phone battery dies, so he calls Sharon using a payphone. Suddenly an electronic signal (later dubbed "the pulse") is broadcast across mobile networks worldwide, turning cell phone users into rabid killers."
Read the book in highschool. It's really good. A bit of a different take on the "Zombie" apocalypse if you you want to call it that. The movie is ok. Didn't like some of the changes they made for the movie. My suggestion is either watch the movie then read the book or just read the book. Definitely don't read the book then watch the movie but that is usually how it goes with movie adaptations of books.