Zim Wiki - Zim is a graphical text editor used to maintain a collection of wiki pages. Each page can contain links to other pages, simple formatting and images.
Scribbleton - The little personal wiki.
Wiki on a Stick - Self-contained desktop wiki
MyInfo - MyInfo is the most versatile organizer for Windows
TiddlyWiki - a non-linear personal web notebook
ZuluPad - ZuluPad is a notepad on crack.