Here's An AP Story that says growing back pain complaints prompted a new California law limiting textbook weight. But some say assignments drawn from the Internet, "e-books" or CD-ROMs will be the real solution. New Jersey is also considering imposing a maximum textbook weight.
Officials there used money normally spent on textbooks for computers. The new school's first students — about 60 incoming freshmen — get assignments from such services as Questia, and Interactive Mathematics, curriculum on computer CD.
See also, School officials keeping eye on new backpacks for a low tech solution.