AutOrg is a personal information organizer that works off-line on your computer and supports easy publishing, encryption and sharing of selected parts of information.
iGTD takes some concepts from Getting Things Done methodology and makes them easy to understand and use in your every day life.
NeO is a powerful outliner/organizer built for MacOS X. Using NeO, you can easily manage and organize chunks of information. NeO supports basic outliner facilities, such as creating, moving, sorting, grouping and combining items.
(commercial) SecretBook is an encrypted personal information database for Mac OS X. It allows you to easily and safely store all sorts of little bits of information like passwords, credit card numbers, pin numbers and software licenses.