I've had a lot of different personal knowledge bases in the past. But not everything was working the way I wanted it to work. So just around a week ago I started my own personal Wiki. I used the free service of wikidot.com to create my personal private Wiki.
As a technologist I organized my Wiki based by the different technology I work in. I have code examples, solutions, helpers, and other things. Also I often find interesting things on the net which I kind of copy to my Wiki by linking to the source and aggregating the needed information so I can use it fast. This is my own personal short-cut to technology knowledge.