DOS-on-USB lets you install MS-DOS 7.1 on your USB memory key. After formatting your flash drive, you can install a full working version of MS-DOS to let you run games or system utilities. The best thing about having a DOS-bootable memory key is you can boot into it on any computer, just like a CD.
You'll find this utility great for times you need to do system maintenance, because you wont constantly have to burn a new CD, just copy the program to the USB Drive. With the DOS prompt, you can even install Windows 95 or 98. Recommended USB drive size: 16MB - 2GB. Version 2 features an auto launch for ease of the DOS operating system.