Corkboard.me allows you to make a corkboard and pin all sorts of things to it – images, videos, text, etc. It would useful at the beginning of the school year when classes are working on introductions and talking about their likes and dislikes, families, etc. A student could make a corkboard about what they like to do, complete with pictures and/or videos of themselves.
You can also make a class corkboard and pin up things such as test reminders, homework assignments, etc. The default image when you click on the board is a post-it note, so you could keep track of all sorts of things using corkboard.me