In case you haven't enjoyed enough movies about zombies and the undead lately, Diary of the Deadsupplies you with yet another opportunity. However, this low-budget film is from the guy who first introduced most of America to the horrors of the walking dead: George A. Romero, who made Night of the Living Dead back in 1968. (So the zombie genre is the same age I am. Cool!)
Diary of the Dead isn't a sequel to the other movies in Romero's Dead series, but it does tend to assume that you know Romero's standard operating rules about zombies. If a zombie bites you or if you die in any way, that's it for you -- you're undead. The undead are cannibalistic, and the only way to destroy them is to destroy their braaaaains. Unlike the other Dead movies, this one is shot as if it were a documentary -- a survivor has pieced together footage from the first night that the dead come back to life.