Recently it was suggested that the Habari project think about using Tiddlywiki
that allows you to save snippets to your TW as a scrapbook of sorts, though I haven’t tested this extension yet.
The formatting in TW is different than MediaWiki, though it’s fairly easy to get used to. There’s also a MediaWiki formatter, which allows you to use that formatting in your TW (which is handy if you are copying info from a MW page. The same plugin author is working on an importer, which I am investigating, which actually allows you to scrape MW entries right into your TW.