FreeOTFE has a "no install" mode, though it does require Administrator privileges to load the drivers. Using this mode is a good way to put both FreeOTFE and an encrypted volume on a portable drive, either a flash drive or a small USB drive. If the drive is stolen or lost, its contents will be inaccessible, and you can use it on any computer where you have appropriate privileges--for example, this is ideal for transporting sensitive data between office and home environments, or between multiple work computers.[pcworld.com]