Hi all,
It seems to me there ought to be a "Downloads" folder within the "Documents" folder that the PortableApps suite installer builds - I often download files from the web onto my USB drive while I'm at the office for use at home, and vice versa.
If there's interest, I built a "desktop.ini" file and an icon that is thematically similar to those already in use, which I'd be happy to donate.