I checked out a program over the weekend called Truecrypt which has the dual advantages of being multi-platform (Windows & Mac), and being free. It can work as either computer-based or run from the flash drive (the latter being Windows only). It’s a very powerful encrypting program that has many high-level capabilities, but once you learn to use the interface (it has very good step-by-step instructions), it is quick and easy to use. As with the Office documents, you will need to record your password since it cannot be recovered if you lose it! Go to http://www.truecrypt.org to download and read the very simple instructions on how to use!