I just ran across this on an East Tennessee radio station's website. They require that callers speak a password on their "Trading Time" show before being allowed on the air. The announcer states the password - I suppose at the beginning and a few times throughout the show - for listeners to remember or write down in case they wish to call in their items for sale. I can't say I blame the station, because where I live two stations air such shows at two different times. I have worked at both stations and I've gotten calls for "the show" during the time "the show" was airing on the other station. Simply put, it was obvious the callers were not tuned-in to our station. The only drawback I see is that these callers who don't listen won't go to the trouble of calling and will email/fax/snail mail their items in, if that's an option. Therefore, I can see the announcer having to potentially fill gaps in the show due to lack of phone calls. I wonder if any area stations require callers to use passwords?