Rescue failing drives with ddrescue
When you need to perform recovery operations on any damaged or failing digital storage media, like a hard drive, USB stick, CD/DVD, or SSD, your first task is to copy whatever you can before it dies completely. Then you can operate on the copy without worrying about doing more damage to the original. GNU ddrescue is a superior tool for this.
ddrescueperforms block-level copies, so it doesn't matter what filesystem or operating system is on the media. It is fast because it copies only the good blocks and passes over bad blocks, and it's automatic so you don't have to babysit. The device you are copying to, like a USB hard drive or second internal hard drive, should be 50% larger than the original. Again, I recommend using System Rescue, which includes
ddrescue. (Replaces Norton Ghost, Acronis True Image, Paragon Backup & Recovery.)
Disk clone with Clonezilla
What if you want to clone your entire operating system and data so you can move it to a larger hard drive, or create a backup for a bare-metal restore? Check out the wonderful Clonezilla, which has the coolest name and mighty cloning superpowers. There are two editions: Clonezilla Live and Clonezilla SE. Clonezilla Live is for bare metal backup and recovery of individual machines, and it runs from a bootable USB stick or CD/DVD. Clonezilla SE clones multiple PCs simultaneously, and very quickly over your network.
Clonezilla operates at the block level on x86 and x86-64 platforms, so it copies any operating system and filesystem. (Replaces Norton Ghost and Symantec Ghost Corporate Edition.)
TrueCrypt is one of the most popular cross-platform encryption applications, and for good reason-- it's easy to use and very strong. TrueCrypt runs on Mac, Linux, and Windows. It encrypts partitions, entire storage devices, and creates hidden volumes. First you create an encrypted volume, and then files are automatically encrypted and decrypted on the fly as you use them. You only need to enter your password when you first mount a volume.
You can share encrypted volumes over a network, and TrueCrypt also has a portable mode where you can run it from removable media, without installing it on the host system.
TrueCrypt is not magical, so use a little common sense -- no file encryptor is proof against keystroke loggers or other malware present before it is installed, or physical possession of your machine when an encrypted volume is mounted and open.
If you would rather encrypt individual files without having to create encrypted volumes, try AES Crypt. It has a nice GUI for Mac and Windows, command-line only for Linux.