Recently I had been hunting around the web for a very lightweight, simple to use, flat file using, php based wiki. And I managed to find one. It's called Pawfaliki
This wiki package is under 50 kb in size, has an easy to use wiki syntax, is CSS based, and has a very cool dark look. It matched my needs almost perfectly.
Test it out at www.pawfal.org
One minor nit I had was how the URL looked.. for example the About page would look like
rather than a nice wiki like
So like any good FOSS denizen, I went ahead and implemented small changes for this. Get the modified sources: pawfaliki052-modified.tar.gz
If you'd like to see the changes, get the diff for the original package at this bug I raised. (Note, I've renamed pawfaliki.php to index.php, and added a .htaccess file). The changes would go in if theres another release (the last one was a while back).
So there. Give this very small wiki package a try.