Wiki on a Stick that lives in one self-modifying HTML file.
Use it in your home or office computer, laptop, USB pen drive (along with Portable Firefox if you want) and even in a diskette!
It can be used as a personal notepad, calendar, repository for software documentation, and many other things.
Activity seems to have moved to a(n apparently begrudgingly created) fork: http://sourceforge.net/projects/woas/ Check the forums for betas and more recent activity.
Easy to install and use! Ideal for note-making-and-storing (on whatever media)