This muscular disc-imaging utility is not kidding around (though we thought the demo might be). PowerISO lets you mount virtual drives, create bootable discs, and generate CD and floppy images. It supports a huge number of image formats, including standard ISO and IMG files as well as files created by almost all popular disc-burning programs such as Nero, CloneCD, and Alcohol120%.
Our one major caveat is that the trial version doesn't let you create images larger than 300MB (most CDs hold 700MB), making it much harder to fully test the product. On the other hand, the trial period is unlimited, so some users may actually prefer this arrangement. Trial restrictions aside, we think PowerISO makes a good pick for intermediate to advanced users.