Even if Windows 7 isn't yet released a fair amount of people use the Release Candidate and are pleasantly surprised.

The BitLocker feature introduced in Windows Vista allows users to encrypt the content of their hard drive. Windows 7 offers an advanced version of this called “BitLocker To Go” which will allow the users to encrypt their portable USB flash drives.

For this first open My Computer and now Right-click on the flash drive icon which you want to encrypt and select the option Turn on BitLocker.

Now BitLocker will initialize the flash drive and you will be prompted to enter a password to unlock the drive. There is also the option of a Smartcard, which is used by IT professionals, being used instead of ordinary password.

In the next step you have to store the recovery key which will be helpful in retrieving the stored data in case you lose your password or smart card. Recovery key is stored as a file and you should make sure that you are not saving it on the same drive that you're encrypting.

When the recovery key has been saved as a file or printed you will get a confirmation message.

Finally you can start encrypting the drive. For this just click the Start Encrypting button.

Progress of encrypting process will be displayed on the screen.

A message will be shown after the successful encryption of the USB flash drive.  

The drive icon will be changed to show its encrypted with BitLocker. The gold lock indicates that the drive is locked up and the gray lock indicates an unlocked drive. 

Right-clicking the drive icon will bring up options to manage BitLocker encryption.

When you plug in the drive to a Windows 7 system next time you will be prompted to enter the password for gaining access to the drive. You can also unlock the drive on specific machines in the future.
You can also use this encrypted drive in XP and Vista. In Windows XP, when you plug in the drive a message will be shown asking you to enter the password for launching the BitLocker To Go Reader. The utility will be automatically installed on the encrypted drive by Windows 7.
BitLocker To Go Reader is a navigation utility like Windows Explorer for showing the content of the drive.

You will only be able to read and copy files with a BitLocker encrypted drive. For adding files or changing them you will have to use a Windows 7 machine.

With BitLocker you can easily make sure that sensitive data on your USB flash drive is safe. Users who has Windows 7 RC1 Ultimate installed on their system can use this feature.