Drag N Crypt Ultra is a Free and portable data encryption tool which might be used to protect your confidential data against unauthorized access. It can be used to encrypt and decrypt files (lock or unlock) by simply dragging and dropping the file onto the programs target window.
SteganoG is a Portable Application that allows you to hide information or store confidential data in a bitmap image file. The image is used to safe guard your data by appearing as just an image to the viewer.
USB Encryption: TrueCrypt is disk data encryption software that can be used to securely encrypt the information stored on hard disk partitions, portable storage media and USB flash devices. It can be run from a USB device in traveler mode.