Everybody geeky is quite likely to have already heard of FM transmitters like this one that lets you broadcast any audio output stream on an FM frequency and tune into it with a radio. I'm a big fan of this gadget and have about 3 around for various uses.
That said, does anybody know of an equivalent video option that will let me tune into a video broadcast via the telly? That would rock! Google didn't help me much in my search... I suppose it's a question of terminology too.