Warner Bros. has apparently cornered the market on hotel key card advertising at this year's San Diego Comic-Con. Some 36 hotels in the area that issue magnetic credit-card-like keys to their Comic-Con-attending guests to enter their rooms will be issuing ones featuring ads for Warner Bros. movies, TV shows and video games. This will be the fourth consecutive year that the studio will have used hotel key cards -- which have become increasingly popular as an ad medium for the film industry -- at Comic-Con. This year's key card for The Lord Of The Rings War in the North video game also provides information on how to register for "a Special Comic-Con Event where fans can experience The Darkness of Middle Earth."