I don't know too much of other projects, but I do know that the One Laptop per Child project has some very large obstacles to overcome itself. The first is cost of internet, which is so high it cancels out the low-cost laptop's purpose. The only way that I could think of to lower the cost of internet would be to introduce more competition into the broadband/internet market in developing countries, which would increase supply. I know investors are hesitant to do so though because of the lack of demand right now, but if the project suceeded in making laptops more common.. the networking would be absolutely neccessary.
Second is the issue of "technology dumping", in that many times we take new technologies, laptops in this case, and set them in a country without much prior instruction on their proper operation. Thus, the technology doesn't do its purpose and its a great loss for the project and the country. This could be more simply addressed that the cost of internet by merely training teachers or counselors on the use of the laptops, and providing them the knowledge of how to make them most effective to the young students.
--jessie