I think having computers at home is the one compelling reason for all the "let's give everyone laptops/ipads" initiatives. It means that everyone has a device they can do typed reports or homework research on. I'm much less convinced that computers in the classroom are a clear value-add in many cases.
I've known a couple of families where the children received take home devices they were expected to use to do further research or school work on, but who were unable to due to the lack of internet. A few had dial-up which can be unusable with some of the education sites (all the js resources take too long to load, time out, and leave the page useless), but some had no internet at all. Some of these families had no heat/ac, to give an idea of the level of poverty. There were no libraries within walking distance either (nor public transit options).
I think the devices are a good thing, because it gives some of these kids exposure to computers they wouldn't have otherwise and if the school handles it correctly they can be used to do work from home (have all needed resources already loaded on the device), but I've seen multiple teachers not be able to account for the most impoverished students lacking internet action (I somewhat suspect the teachers don't always have a choice in the matter either).
You don't have a "pencil and paper" lab that is used the entire school day and scheduled around, and now computers have reached the commodity price point where they don't need to either.
If computers help learning, why have school results essentially been flat since 1970 or so?
Every student at my school was given a laptop (2005, but that practice started years earlier) - but we were in a special situation being a boarding school. Every student having a laptop meant that teachers could reasonably expect every student to write/research papers, install/run software, use email, etc - on their own time (nights/weekends/study times, etc).
My laptop lived in my dorm room, and if I needed it for a class or to go study somewhere I could take it - but that was a 2-3 times a week thing, not every day and certainly not every class. Day (non-boarding) students had it a bit rougher, as they were bringing their laptops back and forth from home every day, lugging them around from class to class.
Even in 2005, I don't think campus could have operated with the efficiency it did without every student having a laptop. Important information was sent out via email constantly (Lotus notes...), BlackBoard for class documents, lecture notes, etc.
But that was our situation. At a day school, I imagine technology is probably a nightmare. If 1 class each day needs kids to have a laptop, that means every student is walking around with their laptop all the time for no good reason. Sounds like a recipe for failure.
Not to mention the effect of "students have this technology so let's go out of our way to use it whenever we can"
1) A large pool of free, open e-textbooks that teachers can customize and contribute to for the needs of their class. Textbook publishers are the scum of the earth and most of their textbooks used in education suck terribly.
2) Access to video explanations/lectures, etc.
3) Adaptive assignments and exams like Kahn Academy that allows students to work on solving problems that are at their level and progress at a different pace than the class as a whole.
4) Easier for students, parents, and teachers to track progress towards educational goals over time.
5) Learning about computers. (Keyboarding to programming...)
Might be some other ways to use computers in education that would pay real benefits, please comment :)