From Modern Solutions:
DiskScience lets you protect your sensitive information without disrupting normal work. You don't need to enter a password each time you access a file. Instead, your information is stored on virtual encrypted disks that look and feel just like normal disks. CDs and DVDs can be copied into high speed, secure (or not), virtual CDs or DVDs. Standard ISO CD and DVD images can also be mounted as virtual CDs and DVDs. Encrypted disks are stored in single files protected with the 256-bit Advanced Encryption Standard (AES) or other user selected encryption algorithm. You can take this file with you. It can be on a USB device, CD, DVD, or shared on a network. The quantity and capacity are limited only by available storage. All commands except install and uninstall work under guest accounts and are accessible from the main application, the system tray, and the shell menu.