When I went to the Lawrence Hall of Science with Janet, I wore a PLoS T-shirt, of course. The volunteer at the museum, a high school student (you can see her here attaching a harness on Janet), saw my shirt and said "PLoS! Awesome!"
I asked her how she knew about it and why she seemed to like it so much and she told me that they use it in school all the time because it is full of cool information, it is free to read and free to use in presentations and such. Obviously, for her and similar students, the material in scientific papers does not go over their heads, no matter how dry the Scientese language used to write them. And a high school is certainly not going to be able to afford subscriptions to a variety of science journals and magazines. So Open Access is the ideal solution to bring the science to the next generation.
As Paul Chinnock says:
No copyright problems stand in the way of a lecturer basing a lecture or a workshop around a discussion of a published paper.
So, if you are a high-school biology teacher (or student), don't be afraid to use Open Access papers in the classroom, in journal clubs, to send feedback to authors and editors and, in cases of more interactive journals like PLoS ONE, to post commentary on the articles themselves. There are no stupid questions...
And of course, the same goes for college classes as well.