Do you care about your data? Use BitLocker To Go

You probably carry important documents in a USB Flash drive, care-free, assuming it's not likely it could get lost. But when it happens anyone can take hold of your precious documents. Fortunately you can encrypt your flash drive with Windows 7 Bitlocker To Go technology. Nobody except you and whoever knows the password you assign to the encrypted drive can get access to it. There are some caveats, though. In Windows XP and Windows Vista it will have read-only access and if you forget your password and did not create a "recovery key" your only choice is to reformat the flash drive. You can also use it in external storage and certainly in the internal hard drive your system is running on. Watch this very educational video on the subject.  I lost a 4GB flash drive... I learned my lesson.