Document shredder for your mac.
This app provides a widget in the dock of Mac OSX. Drag and drop your documents into the app icon to permanently delete them. It is DoD 5220.22 M compliant. Additionally you can keep it in the dock to use it exactly the same way as the trash.
It's absolutely free, easy to use and DoD 5220.22 M compliant. It comes under MIT licence. You can lock it to OSX dock, it will work the same way as the trash. The file erasing is animated so you can keep an eye on it.
If you care about security and want to erase your file securely, iShredder is made for you! It provides you a safe and easy way to delete your files properly. Drag & drop your files into it, they will be permanently delete and unrecoverable.