Pandemic is causing universities and high schools to close down face to face gatherings and move to online media. The good news is that tools are available, free or inexpensive, and (most) don't require a software engineer to set up; the not as good news is that knowing how to use video, Slack, webforums, blogs, etc. is not the same as knowing how to teach well with these media. Good teaching is hard, and teaching well online is harder. And right now, many teachers are being forced to dive into the deep end of online teaching without instruction in how to do it well. However, the same recentering of attention on student participation and collaboration -- what I and others call co-learning -- can elicit enthusiastic engagement and rich dialog online as well as in the physical classroom. I taught blended learning courses for ten years at UC Berkeley and Stanford -- three hours of face-to-face meeting each week, with forum, blog, and wiki learning activities spread over the week between classroom sessions. For eight years, I taught my own online courses at what I called "Rheingold U."