There was a high-end "audio" power supply discussed on diyaudio in the last year or two, it was pretty much this at 60Hz, one capacitor was charged from the rectifier while another one powered the audio circuitry, and for the next cycle (or half cycle) they were electronically switched. The point of this was the audio circuitry was "never powered directly from the line" and so was supposedly isolated from all that horrible noise and trash on the power line. It might have been psaudio (looking at their other products it seems about right) but I don't see anything quite like that on the site.
I can't find the thread here or the device on the web, there's too much "pollution" in audio power supply discussion! 😀