This is a Windows program for saving and restoring images from removable drives (USB drives, SD Memory cards, etc). It can be used to write boot images (i.e. ubuntu-12.04-preinstalled-desktop-armhf+omap4.img) to a SD Flash device or USB flash device, making it bootable.
Win32DiskImager supports writing an ISO image to USB too, which is very valuable right now with the Ubuntu releases 14.04 LTS - 15.10, because there are problems with the Ubuntu Startup Disk Creator.
The program and source code can be downloaded from here.
This tutorial subpage with screenshots illustrates how to create a USB boot drive from a Lubuntu ISO file. It works in the same way for all current Ubuntu family iso files including the Ubuntu mini.iso version 14.04 LTS (but mini.iso version 12.04 LTS is the only exception).