How to install FreeNAS to USB stick

Note: This post is more than an year old. You can still use it to install FreeNAS on USB but I strongly recommend you to read the new one first which is much simpler:

Installing FreeNAS to USB stick (new and simpler way)

FreeNAS is an Open Source Storage Platform based on FreeBSD and supports sharing across Windows, Apple, and UNIX-like systems. It comes with a lot of protocols and services