One of the best ways to learn about any system is to see examples of what others have done with it. Here are some interesting TiddlyWikis:

• Mosaic Muse: shameless self-promotion, but this Zettelkasten-like system should be a nice complement to this book. I have several other wikis, but this is my largest public TiddlyWiki and where I do a lot of my TiddlyWiki-assisted thinking.
• Interactive Historical Atlas of the Disciplines, a beautiful catalog of the branches of science over time.
• The Community page on tiddlywiki.com lists a number of wikis.

If you have a public TiddlyWiki you'd like to see on this list, click the send feedback link below and send over a URL and description.

The TiddlyWiki Links Aggregator is a community-built collection of TiddlyWiki resources (it probably does not surprise you to learn it is built by compiling other people's TiddlyWikis into a TiddlyWiki). You can find some example wikis under the Example tag.