I also have a stack of academic papers I've read. This is 58cm (23 inches) high :
I haven't counted how many papers there are in it, but extrapolating from the above I'd say at least 500. I print out everything I read, because the links to paper don't go dead as easily as the links to web sites.
These aren't all my papers, either: I have hundreds more in my office at the university, all of which I've read and all of which are either filed or are in the process of being sorted for filing. I bought another 10 filing trays for them earlier this week.
These are all, in some way, related to virtual worlds. It used to be that you could read every article written on the subject in two days. Now, they're being produced faster than I can keep up. It's hard enough just reading the books (there are 12 unread ones in my pile, plus two partially-read ones).
Still, if you want as wide-ranging a view as possible of a subject, this is the price you have to pay.
Oh, the baseball cap on the top is from the Technology Intelligence Group. For some reason, it lives there.