Anybody have any experience on it ?
You could just google it. It's not an esoteric secret or anything. You either use a shift register if you only need them going one way input or output or you buy a pin expander ic and talk to it with SPI or I2C depending on which one you get.
Stevemoretz:
Anybody have any experience on it ?
What is "it" exactly ?
Have you run out of digital pins and if you have then have you used the analogue pins ?
Could you use a single analogue pin and detect several different inputs, particularly from switches, by use of a resistor ladder that gives a different voltage that can be detected using analogRead() ?
Does it come with the pins soldered in already? If not, get headers with extra long pins. Otherwise wires will work to extend them.
If that's not what you're looking for - provide detailed explanation of what you want.
Yes, clarify 'extend'. Do you want a greater number of pins, or pins of greater length?
And if more pins: for what purpose?
OP only asked how to extend the pins.
Leo..