After creating a portable Scribus based on someone else's code, I decided to try creating a portable app myself, doing the launcher coding myself. (I code with Autoit rather than NSIS)
RSSOwl is an open source RSS Reader. Even though they provide a non-installer download, it still saves profile files on the computer itself. So, I've put together RSSOwl so that it does not do this.
You can download it here:
.Zip, about 5.3MB
Tell me what you think. Tell me if you encounter any problems. (Most problems you encounter are probably RSSOwl bugs... so tell them)