I would note that another way of explaining the ideas behind my recent posts on one-to-one laptop initiatives and IT infrastructure in general (here and here) is to point out that this is essentially the "Trojan Horse" strategy devised by OLPC, applied to US schools. You find very conventionally convincing ways to almost completely offset the cost of hardware and software (which you keep quite low) as a way to get your (subversive) technology into schools and keep it there. In the case of OLPC, this means pointing out that many countries in the developing world spend about $100 every four or five years per child on textbooks. If the laptop can replace the textbooks at that cost, or close to it, the program can be nearly budget neutral. In US schools, there are additional pieces of technology that can be replaced by the laptop, like graphing calculators, digital cameras, and sensor readers, to offset the cost of an inexpensive laptop and make the project sustainable in a district's annual budget rather than reliant on the feast and famine world of grant dependency.