The document discusses several free software tools that can be used for encrypting data stored on USB drives, files, and hard drives. It describes tools like Rohos Mini Drive and DiskCryptor which allow encrypting USB drives by creating hidden and encrypted partitions that require a password to access. It also mentions file encryption tools like 7-Zip, AxCrypt and CryptText that allow compressing and encrypting files with passwords. Additionally, it lists disk encryption software like TrueCrypt and FreeOTFE that can encrypt entire drives or volumes and decrypt files on-the-fly.