Do you have lots of sticky notes lying around with various useful information jotted down? Or many lists of books, movies, website logins, personal contacts, or things to do? Can you find them when you need them? Well, I often couldn't. So here's my answer.
Some would call TreeLine an Outliner, others would call it a PIM. Basically, it just stores almost any kind of information. A tree structure makes it easy to keep things organized. And each node in the tree can contain several fields, forming a mini-database. The output format for each node can be defined, and the output can be shown on the screen, printed, or exported to html.
See the TreeLine homepage for more info.