You can get it for free at thinkingwithportals.com/music/.php
You can buy Portal 2 when you are 10 years or older ESRB: E10+
iTunes, its actually the whole Orange Box soundtrack.
Urm... you just buy Portal 2 from Steam and then play it...
The Lion King 2 was not as popular as the original, which is why it isn't on iTunes. But it is possible to buy the soundtrack on amazon.com.
Ask your friends.
You buy it.
You need to buy Portal in order to play the mod Portal: Prelude.
Best buy
One can buy the original soundtrack to the 1983 movie Scarface from sources such as Amazon and iTunes. Another company that sells this soundtrack is CD Universe.
Online.
You can buy the soundtrack from places like Amazon.
You can buy the soundtrack at a store such as Walmart or a music store, or you can buy it online, or you can listen to it online at www.youtube.com.