I’ve never liked wikis. I didn’t like wiki syntax, and I thought they always looked really slapdash and ugly. But, I’ve seen the light. I’ve seen Instiki (found via a whole lotta nothing. It’s painfully easy to install, and even easier to use. You can use Textile, Markdown or RDoc with it, and it gives you basic formatting tips right next to the editing window, so there’s no chance of getting confused. In OS X, it even gives you a Wiki menu item, which makes using it for random meeting notes and to-do lists REALLY easy.
If you’re looking for a personal note-taking app, or a wiki for your team, Instiki’s the way to go, really.
Instiki is really amazing. The developer who came up with it also coded Basecamp from 37signals, so he already has “street cred”.
My company is using a variant of the Instiki codebase (with our own UI *ofcourse*) for client projects involving knowledge management and bug tracking. Good stuff!