Nokia N900 - Maemo Video Overview

Maemo is a computer architecture platform built using open source Linux components. Maemo is one of Nokia’s core handset platforms characterized by high performance, new cool UI principles and Internet philosophy.

To know more about The Maemo platform.

Linux From Scratch

Linux From Scratch (LFS) is a project that provides you with step-by-step instructions for building your own custom Linux system, entirely from source code.

It's a very good for whom want to understand Linux in more.

LFS also provide a LFS LiveCD

A LFS LiveCD is a CD that is able to boot your system into a 'live', working operating system, independent of anything on your hard drive. It's a little different than an installation CD, which boots your system into a program that will guide you through the installation of some system onto your hard drive. With a LiveCD, you have an entire system contained on the CD and with that, the freedom to do nearly anything that a system installed on your hard drive can.

The LFS LiveCD is geared specifically toward providing a reliable host system for the purpose of building Linux From Scratch. Therefore, it may not be what you would envision as a "perfect" Linux system. It should, however, provide you with a comfortable enough environment so that you can, in turn, build your own "perfect" system.