Raspberry Pi Forums

I have a few 4066 chips lying around and was wandering if anyone has considered using them as a cheap/simple method of level shifting when interfacing the Pi GPIO pins to external devices?

It's quite amazing what you can do with bilateral switches.
Power it from 5v, attach one side to 3v3 and the other through a pull-down resistor to ground, and you've got a buffer or level translator - the control is at 5v, the output at 3v3.
Attach one side to ground and a pull-up resistor to 3v3 on the other, and you've got an inverter.
Parallel two of them, you've got a NOR gate. From there, you can do almost anything (you'd need quite a few to build an ARM processor, and it would be rather slow)