"It used to be illegal to plug anything that didn't come from AT&T into your phone-jack. They claimed that this was for the safety of the network, but really it was about propping up this little penny-ante racket that AT&T had in charging you a rental fee for your phone until you'd paid for it a thousand times over."Once you've read it, head over to the EFF's site and donate — they're the folks who defend our digital rights against absurd FUD.
"When that ban was struck down, it created the market for third-party phone equipment, from talking novelty phones to answering machines to cordless handsets to headsets -- billions of dollars of economic activity that had been supressed by the closed interface. Note that AT&T was one of the big beneficiaries of this: they also got into the business of making phone-kit."
Update: Because the Internet is so frickin' cool, and because Cory used a Creative Commons license for his talk, there's now an audio version available, as well as a wiki-fied version for annotation. Nice!