Woomba jokes aside, Apple's iPad is tantalizing from an education IT standpoint.
I think a class set for $13,500 (30 x $450) would be an amazing opportunity. That's still a steep price tag, but gradually rolling them out, at district volume prices might get you down to 1 cart/3 classrooms pretty quickly. Sure, a lot of teachers might not be the best fit. But the sort of closed-environment apps you could do on here would be amazing. I've generally taught in lower income schools, everything from K to 12 and I could use these with every grade. You usually can't count on kids having easy access to high speed internet outside class and so just the ability for targeted instruction ramps up dramatically.
The ability to set up custom content that targets ability would be incredible. As you go up in grades, the ability spread gets worse and worse. With an interactive textbooks the sky is really the limit. You could do variable reading levels in science or history textbooks. Assessment, both formative and cumulative could be in realtime, linked to parent emails. Classwork could be tracked. Rewards/incentives could be offered. The possibilities for student-centered/driven instruction are really opened up.
The big difference between the tablet and the desktop/laptop is input. Not only are they mobile, meaning they could be used in group-settings or field-work. But they'd offer a broader range of tactile accessibility options. Students are notoriously disorganized and the ability to save a notefile might be a real benefit to many students. Being able to incorporate the tablet into instruction on a daily basis just frees up a whole range of options that wouldn't be practical when limited to shared lab use.
Cost and theft are definitely concerns. But textbooks aren't really cheap either. Weighed against the benefits, not the least of which might be teacher time spent waiting at the copy machine, I think less than $500 is pretty awesome.
But this is the kind of thing that requires real leadership on. The more you put into it, the more it's going to work for your school. With some bright IT folks, in touch with a good team of tech savvy teachers and administrators and there are a lot of really neat opportunities for even the most tech-resistant teacher.