Just brought to my attention: SlateUp. More to follow as it evolves. Membership now by invitation to .edu accounts. Check out the site for more information. Sponsored by Fortune 500 companies. More to follow here. Join us:
" ... SlateUp is a student community built by students. Our goal is to transform the way we learn and facilitate free flow of knowledge amongst students. Through Slateup.com we have made a few tools available to help you do just that - Share Knowledge! We will keep adding tools to the site based on your suggestions ... "