Been toying with a portal, nicknamed Orsus, for people to share their notes stored on caldav servers. This would make it possible for people to have a personal wiki published on the web without dealing with hosting.
The idea is that people share the calendar subscription link to orsus and it will render a personal wiki/garden + RSS feed.
iCal supports most stuff you'd expect from a personal wiki like note linking and tags.
This is kind of like a poor man's version of #SolidProject where the datapod is your caldav server.