Infogr.am looks like a pretty easy tool for creating infographics that can be linked to or embedded. The selection of templates is pretty limited, but the site is still in beta.
The main problem with the site is that you can only log-in using a social media site like Facebook or Twitter. That makes it usable for teachers, but, since those sites are blocked in most schools for students, they would not be able to create their own.
Nevertheless, I’m adding it to The Best Resources For Creating Infographics.