Padlet's motto is that it is the easiest way for online collaboration. That's true, indeed. There is hardly any other tool that makes it so easy to start without much of a registration procedure - or, actually, if you use it for brainstorming, without any registration procedure at all.
Even if you (as a teacher) create a Padlet Wall for your students' brainstorming activities, it hardly takes you more than 30 seconds. If you still feel like having an explanation or seeing more ideas what you can do with Padlet in the classroom, you could consult the Padlet Blog Entry of HPS Digital (the blog is run by the admin of Hopkinton Public Schools).
Padlet also offers a plan for schools, including better (classroom) management, the possibility of creating ePortfolios, a controlled environment and more security. There are also some video tutorials online showing the procedure of creating an ePortfolio with Padlet. Here is an example :-)
As an incurable Mahara-lover, I appreciate the possibility to create Padlets and to embed them into Mahara views. Padlets can be embedded in many environments.