Hello,
I think it's time that you include an app that will create image files out of files on your hard drive and not just burn them to or from CD/DVD. Free ISO creator (http://www.minidvdsoft.com/isocreator/) is a nice, simple app. Honestly, it doesn't have many options (creating ISO files from files/folders is the only one).
I would like to see even a better portable app than this. The one that can create iso, bin/cue files, compress them, edit them, and so on.
InfraRecorder Portable can. I think cdrtfe Portable can as well.
Sometimes, the impossible can become possible, if you're awesome!
trust me the best portable and best one for ISO making is called "LCISO" so simple just click what u wanna turn into ISO then walla