Well, that is exactly what I am :).
I just can't stop myself from downloading stuff (usually electronic articles, say, PDFs). To be more precise, whenever I come across something that I think might be helpful to me (an arixv article, for instance), I'll try everything I can to get a copy onto my hard disk, even though most of the time it is not of the slightest use to me (and then I will yet try to convince myself that it might be helpful for "future reference"...).
Although the truth is I won't even take another look at most of the downloaded stuff as soon as I finish downloading, I still must keep downloading. Virtually everything that is useful, or seems to be useful, or looks as if it will be useful, I can't resist trying to download it. I confess that I seldom use any of my downloaded files, but just owning them, just knowing that they are right there stored in my hard disk, I will somehow feel a bliss, an incredible sense of security, just like a miser counting his gold coins.
So here I am, a hopeless "download-aholic". What word would you choose to best describe me?