I seem to remember a while back that I saw a device that you plug into any phone line and it allows you to make calls all you want, but any incoming calls get the busy signal. There was also a device just like it that worked the same except incoming calls got the disconnected line message. I can't for the life of me find the link but I have a friend I want to prank and I think it'd be pretty fun!
Anyone know what I'm talking about?
Any help is GREATLY appreciated!