Online courses life restrictions on tools when it comes to student projects and their impact. In a number of courses, students use Google Sites (a fairly straightforward tool) to create group or individual projects, and to promote awareness among colleagues and community. In several other courses, students create videos, either as a check-in assignment or as oral/visual presentations of their papers.
It appears that Tackk allows one to make both an engaging presentation of content with rich multimedia and invite participation through the commenting feature.
To learn more about sharing and commenting, check out this announcement by Tackk.
I came upon this resource by reading Free Tech For Teachers blog, which is prolific and is mostly geared towards K-12 audience. However, there are all sorts of universal resources one can use in any setting.