Linux is everywhere, but you might not be aware. Linux has pick up really fast and integrate into different devices from IP phones to TV's to embedded system to space robots.
You might already be a Linux user and you don't even know it. You might have seen Windows running on different devices like the Pocket PC, however Linux doesn't need a display and can run on systems that don't even use it.
Here is an example:
This might look by a regular TV and far from being a computer. However this TV runs linux. Thanks to the Linux OS working there you area able to get more features that most TVs won't get. The difference would be the user gets no exposure to use this OS. However some manufacturers do let you play with the Linux OS and is consumer friendly:

Nokia, the cellphone manufacturer sells an Internet tablet that runs Linux on it. You can use some of the Linux applications that you will otherwise use on a Linux Computer. Things like Instant messengers, chat, browse the internet, watch video and audio. Here is some screenshots of the common activities a computer user might do:

Listening to audio

With an Opera browser editing a document online
So linux is growing rapidly and the plans are vey ambicious. Expect Linux to be the default operating system in places where money is really a challenge. The most needed population which is the children in 3rd world country could get a Linux laptop before 2010 if the One Laptop Per Child mission succeed. Here is just a taste of what the
OLPC is doing in Uruguay.

So with all these development, getting to know Linux could be on the not that distant feature. For this reason TUX university is formed here at learnhub and expect new and exciting things teaching teachers learn this technology.