From QSX Software:
Undisker is a disk image utility that can open, create, and extract ISO files. ISO files are images of CD-ROM disks; they are widely used for storing contents of entire CDs. Usually, you have to burn an ISO file on a CD to see or extract its contents, but now you can simply open it in Undisker. Undisker can work as an ISO extractor: you can open ISO files, browse them, and extract their contents to your hard disk without burning the ISO file on a CD. Undisker can extract ISO images created by all popular CD recording programs. You can also use Undisker for creating ISO images. Undisker can create ISO files by capturing your CD-ROM disks.
You can use ISO files for creating backup copies of your CDs or for transferring CDs through the Internet. The undisker interface is easy to use and familiar for anyone who has used WinZip or Windows Explorer. Drag-and-drop support allows you to handle disk image files just like ZIP archives--you can extract any file from the image by simply dragging it to the desktop, or you can view files by double-clicking them just like in Windows Explorer.