In this season of buy one get one free it's kind of interesting to see the marketing line "buy one give one"... However it's still interesting (even though they got to look at the math).
The vision is education and working on educating children that otherwise wouldn't stand a chance. The One Laptop per Child (OLPC) organisation is mostly focused on Africa and third world contries even though I would say that some inner cities in the US could need this help just as much (based on some schools performance compared to where you would think they should be using the available resources and location).
Anyway they have developed a laptop with handcrank and all running a linux operating system (read free - open source) to ensure that once you have the laptop there is no extra cost.
It's intended to be a $100 laptop which is now being sold in some stores as buy one give one @ $400 ($200 pr. laptop). The good news is that the give away is tax deductable in the US so you got a instant $200 tax deduction on top of everything :-).
If you want to know more check out the NY Times article on the mission or the OLPC website.
I think it's an interesting idea and kind of tempted. But on the other hand $400 is pretty close to what you could get a "normal" laptop for sooo... I guess you should be looking at it as a donation of a laptop.