Old wine in new wineskins. A better idea is to do what some schools already which is to use a single blanket permission form at the start of the year, and allow parents to opt out of specific activities.
A local installation of WordPress would allow each student to have his or her own blog. Students then can create posts and upload media and other documents.
As an added benefit, students can comment on each other's work.
Google "kiosk browser mode"