USBImager - A very minimal GUI app that can write compressed disk images to USB drives.
Win32 Disk Imager - Create and restore image backups of disk drives.
ROSA Image Writer - Rosa Image Writer is a program for writing images to a flash disk.
Rufus - Rufus is a piece of software that allows you to transform a portable drive, like a flash drive or other USB drives, into a bootable drive that can be used for a variety of purposes. Read more about Rufus.
SUSE Studio ImageWriter - Utility for writing raw disk images & hybrid isos to USB keys.
ApplePi-Baker - ApplePi-Baker is free software for Mac OS X for preparing NOOBS SD Cards and flashing SD Cards.