Part of the Mathematical Association of America (MAA)'s Mathematical Science Digital Library (MathDL), this site offers resources for math teachers who want to help their students better communicate as mathematicians. The site includes assessments, rubrics, sample assignments, and things that teachers might consider before adding a communication component to their math classes.
Produced by (Channel) Thirteen in association with WNET, 2012. This site provides students with real-world examples of how professionals use math: in music, fashion, video games, restaurants, basketball, and special effects. Primarily created for students in middle and high school.
From Bowling Green State University, resources provided by their Center for Teaching and Learning. They use Shelfari to collect and describe their Library Holdings; the Center Archives has an excellent compilation of favorite websites; and the Teaching and Learning Guides are also helpful.
Posted on website ClassTools.net, this tool helps instructors (and others) to select names from their class list at random. No creator name (or date) is given.
From their About page, "edshelf is a directory of websites, mobile apps, and desktop software that are rated & reviewed by educators, for educators. We decrease the friction of using and procuring effective technology into the classroom." Concentration is on K-12, but these apps might also be useful for postsecondary teachers.
A tumblr created by Luke Neff. From his "About" page, he describes himself as a teacher. This page has over 400 writing prompts, most of which include a photo or illustration, a quote, and then a suggestion for a writing exercise.