CiphSafe provides an easy-to-use method for storing account/password pairs as well as any general notes you wish to keep safe. The application encrypts with 320-bit Blowfish, includes random password generation and has a very clean interface.
Requires Mac OS X version 10.4 or later (use 1.2.1 if you need a version which works on 10.2 or 10.3). CiphSafe is OpenSource software and released under the BSD license. If you want to know more about the project you can visit the Sourceforge project page.