For those of you who may have missed an EDge21 featured post or who didn't have the opportunity to look at some of them during this past week, here's a second chance.
Classroom is a new, free tool coming to Google Apps for Education that helps teachers easily and quickly create and organize assignments, provide feedback, and communicate with their classes.
Amazon School Lists is a new way for K-12 teachers to create and share online back-to-school supply lists with parents.
ChalkUp is a student engagement platform designed to foster real-time school-work collaboration, learning, and studying, ChalkUp enables students to ask questions, discuss and share interesting educational content, and work with each other.
The Math Open Reference Project is free, interactive math textbook on the web covering high-school geometry.