Thing #10. Wikis

I really do like the idea of a wiki, but I am having a hard time truly identifying the "good" wikis from the "bad" wikis. There are some that are just so much more user-friendly than others; they are easier to search, and information is much more accessible.
I can really only wrap my head around creating basic ones - the example of the camping trip supplies in the Common Craft video, or one for the members of my book club to use for figuring out a date to meet and borrowing books from each other. I have so much more to learn on wikis - and I'm just interested enough in it to keep on learning.