Your favourite “Loosely Coupled Teaching” example?

As part of my new ongoing efforts to collect and re-present ‘Best Practice’ examples of what I’ll call “loosely coupled teaching” I am really interested to hear from readers their single best example of a course (ideally one reachable on the public internet) taught using contemporary social software/web 2.0 tools outside a course management system. What have you seen that really made you sit up and say ‘Wow! it works!’ (And before anyone starts, I am asking for ‘course‘ examples in the context of formal higher education…I know, I know, but that is the audience and context I’m working in right now.) If you had one chance, less than 5 minutes, to convince a colleague to give up their CMS addiction and teach out in the open using general web tools, what is the best example you can point them at to convince them? – SWL