Hey Mr. Microphone! I'll Be Back To Pick You Up Later!
When we talk about mobile audio around here, it's usually a cool car stereo, portable 8 track, or a slick boom box. In 1979 a commercial for a new on-the-go audio device was so pervasive that you just aren't a kid of the 70's if you don't remember Ronco's Mister Microphone.
Mister Microphone was the first wireless microphone I'd ever seen (at least the first I'd seen for sale at the grocery store). Inside it was a low powered transmitter that sends a signal to a nearby FM radio. According to the commercial, Mister Microphone can make you into a rapper, professional singer, or a letch in a convertible.
The few times I used a Mister Microphone, I remember it being a bit flaky. Legally speaking these kinds of devices had to be really short range (can you imagine if your drunk uncle had the power to be on every radio in the neighborhood?), and finding the exact frequency on your FM receiver could be pretty fiddly.
Still, I'm for any product that lets regular people take control of the media - even if it's just their car speakers. Ronco advertised lots of other "necessities" like the Pocket Fisherman and the Veg-O-Matic, but Mister Microphone is still a kitsch classic that speaks for itself.