Callpod states unequivocally that their Keeper application is engineered to be the most secure and easy-to-use application available for storing all your secret information. The reason they say is they use military-grade 128-bit AES encryption technology. On top of that there is a free iPhone/iPod Touch app that works separately or in complete symmetry with the desktop version.
The Basics
Mac Application: Keeper Desktop 2.1