Piazza is a great tool to facilitate collaboration and discussion between distance education and on-campus students, and it has greatly improved our ability to respond to student's concerns and questions.
It was way better than anything Harvard designed for this purpose. It's a much more satisfying knowledge-management / Q&A experience than the corporate sharing system, and of course much better than pure "bulletin boards." The best parts: 1) I don't have to answer the same emailed question four times, and then a fifth time realizing I might as well email the whole class. 2) The inbox-style layout. Awesome interface overall, feels very thoughtful. 3) The incentive for a quick response, in the form of the average response time at the bottom. Very motivating! 4) Seeing posted questions in email, with a follow system for responses. Great balance of using up my attention. 5) It was nice that you added a mobile app.
I really enjoyed using Piazza. It was much better than the default classroom portal at Harvard for class discussions. I like that I did not have to check for new postings (email notifications) and that I could use the visual feedback (icons) to quickly scan for changes since I last logged in.