I would like to see WinCDEMU as a portable app. It is a tool that allows you to mount and unmount ISO images under Windows. It's really useful for netbook owners who don't have a CD drive, or for those who don't wish to risk scratching their CD's.
If you want to download a portable version, it is available for download here:-
The portable version is already released under sourceforge, and is already portable. All it would need is tweaking with a splash screen and repackaged up to make it an "official" portable app