SanDisk Memory Key comes with it's own encryption program, you don't need to install anything on the end machine.

The new version of CruzerLock, called CruzerLock 2, will enable users to encrypt, decrypt, compress and password-protect personal files – even entire folders – stored on Cruzer USB drives. Operating on the Windows platform with drag-and-drop functionality, the software will be available first in English, then in other languages.

“Because of the growing concerns over identity and intellectual property theft, we’ve made it a priority to enhance all SanDisk Cruzer drives in the family – not just one model -- with a more comprehensive and versatile security program,” said Eric Bone, SanDisk’s director of retail product marketing. “This new software uses an industrial-strength commercial algorithm that has 448-bit Blowfish AES encryption and password protection, which is orders of magnitude greater than our original CruzerLock.”
http://www.pdatoday.com/more/A2110_0_1_0_M/