BitLocker To Go is an easy to use encryption technology that will allow you to encrypt the contents of a USB stick or drive.
Microsoft has posted a full instructional video at the address below. It describes how to write data to USB keys using BitLocker ToGo and explains BitLocker ToGo Reader that is required to read the USB keys on computers that are running previous versions of Windows.
When a BitLocker-protected removable drive is unlocked on a computer running Windows 7, the drive is automatically recognized and the user is either prompted for credentials to unlock the drive or the drive is unlocked automatically if configured to do so. Computers running Windows XP or Windows Vista do not automatically recognize that the removable drive is BitLocker-protected. With the BitLocker To Go Reader users can unlock the BitLocker-protected drives by using a password or a recovery password (also known as a recovery key) and gain read-only access to their data.
Download is available here - http://www.microsoft.com/download/en/details.aspx?id=24303
ITS offers an Encryption Service to assist users in setting up Windows7 Bitlocker.