In addition to the bags that Warner Bros. is offering at Comic-Con this year, they're also bringing back the hotel room keys that they did at last year's con. A total of 29,000 branded room keys, designed to promote DC Comic's digital comics application, Batman: Under the Red Hood, V, Smallville and Supernatural, will be distributed at 36 participating hotels throughout the San Diego area during the week of the Con. You can find more details here, and check out additional key artwork after the jump.