Actually, in theory, if you were to open a CB radio and replace it with a crystal modifying it to operate in the 469 mHz range (the area where most McDonalds operate), you could get this to work and it would no longer be a joke. HOWEVER, I don't know what kind of crystal you'd need and what frequency it would have to be.
Let's say you were to do this with a standard 40 channel CB radio, like a Cobra 29. As long as you use an antenna suited for the newly allocated frequencies (using a CB antenna for 460 Mhz would give you high as hell SWRs which would fry your radio) you would be OK.
But I just remembered something: You'd have to either use an FM CB set from the UK or modify something like a Uniden HR-2510 which has FM capabilities. Trying to use an AM set to talk to people on FM sounds like fucking shit- I know, I've tried many times on 11 meters and in that general area...
So as soon as I find out what crystal you'd need, I'll get back to you and make a post debunking this- so that you all can go out and buy an expensive 10-meter radio to terrorize your drive thru crews!