From Mac Attender:
PDF Protector is an easy to use utility to protect your documents. Supports Adobe Standard 40-bit Encryption and Adobe Advanced 128-bit Encryption. Password protect opening of the document. Unlock password protected documents. Prevent printing of the document. Prevent copying and changes to the document. Easy to use. Compatible with all common PDF readers, such as Preview.app or Adobe Reader Does not need Adobe Acrobat software.