USBWriter is tiny Windows tool that lets you write an image file directly to an USB drive. It requires no installation and depends on no bloated framework, it's just a little program that you may put on your desktop.
This tool is useful to create a bootable USB disk from a Linux Live CD image file such as Ubuntu, Fedora, Gentoo or ArchLinux.
Please read the wiki in case of issues, every possible error or misbehavior is explained.