How to set up Raspberry Pi as a WiFi access point

There are a number of useful Raspberry Pi (RPi) projects out there. One interesting use case is to turn Raspberry Pi into a WiFi access point. The advantage of having a RPi-powered WiFi access point is that you will have ultimate control and customization of the access point, thanks to the flexibility of the mainline Linux powering the RPi board. In this tutorial, I will demonstrate how to build a wireless access point using Raspberry Pi.