While extraordinarily cheap, the machines behind the “One Laptop Per Child” project won't be lacking in security at all. According to the article, MIT's $100 laptop actually supports very advanced security features, such as walled gardens for programs to run in, a hardware-locked BIOS and many other features. The biggest concern, though, was the laptops ability to “mesh” with other units nearby. Being that it allows the laptop to remotely upload and download files, it's likely the first thing to be compromised. What's most interesting about all these security features it that they can apparently be turned off, in the name of learning:

Walter Bender, a co-founder of MIT's Media Lab who is overseeing software and content on the $100 laptops, said a major principle in the project is that children should be able to tinker with the laptops and learn how they work. To that end, these security measures can be turned off by the PCs' owners.
The project is one of the most ambitious worldwide PC initiatives ever conceived, and being such a high-profile target is going to leave them open to attack. Will these laptops be able to retrieve updates from across the globe should they be required?