When I was in English class, there was no reason for me to have a computer. We did the reading at home and only did discussion in class.
When I was in Math class, we had computers, at least in Calc and DiffE. I spent most of my time making Mathematica animations. Tests were designed so that a) you could do them by hand (no calcs even) and b) putting them into Mathematica generally made them harder, as Mathematica generally didn't solve them in a useful way.
In German, we didn't need computers because we did the readings as a group. Computers would have been a distraction. Possibly, having an iPad like thing and reading in a program that let me take notes on the page itself, would have been ok, but that would have only added up to equivalent with the book. And would have been heavier...
Chemistry we didn't need a computer, as we were doing experiments half the time. Maybe a computer would have been nice when taking notes. I generally took notes on paper in college when I had a computer, though...
Computer class...was f-ing worthless. We learned to type and to use excel, and then we learned to type 3 more times. I made friends with the lab manager. He let us come in on weekends and run HL and CS tournaments.
Biology...same as chemistry.
History...I guess digital textbooks would have been nice, although it was a mix of English (read at home and discuss in class) and lectures. Again, for the most part, it would have just added up to pen+paper+letshopeitworks.
Of course, there wasn't a lot of computer based curriculum. Nowadays, that might be different. Having 2 teachers for parents, I'm gonna go with it might be different, but it isn't better. My mom teaches kindergarten. They require her to use her smartboard during class a certain amount of time, but they don't help pay for any training or anything. There are only a few pre-made courses for it (for kindergarten...), none of which work with the curriculum she is required to teach. Meaning, on her own time, she has to learn a new and proprietary programming environment (again..this is the 2nd brand of smartboards in her school in 5 years). I went to an even better school (with way more money) than the one she teaches at, and they had no idea how to integrate computers (except the math teach, but he was different in a lot of other ways).
Basically, depriving kids of computer literacy is a bad thing. Forcing computers into classes that have not yet fully adapted to them, including the distractions they bring to the kids and the teachers, is probably even worse. You can learn computer literacy at home. Many people can't afford a computer at home, so they can learn it in the library. Or the school can focus on making the computer class *actually worthwhile*. My point is, kids aren't going to be deprived of the ability to learn to use computers, especially not at a school where the choice is 2 computers per child or 1?
Your argument makes sense for kids in 3rd world countries re: the OLPC project. For kids in posh schools in developed countries, the argument is more like depriving a mechanic of one of those super expensive factory provided diagnostic tools and giving him the 3rd party one instead. At poor schools, it's more like having a couple wrenches to share, and one of those diagnostic tools for the kids that have really proved themselves.