Jooce - Power To The People
Jooce is free, quick and it takes less than a minute to register for an account.
With an account you get a public and a private desktop with unlimited storage space! Below are a few screenshots from my public desktop.
I've been searching for a tool like jooce for a long time - an online space where students and teachers can upload and swap files and not overload the school's server. The classroom possibilities are enormous. Check it out.