Down here also looking for things useful to you that others have discarded, although you might also get conventional recyclables (cans and bottles), or on a bad day, something to eat.
Although, our university students have cut out the middleman (the dumpster) and organize a donation event at the end of the term.
It's not really Science. I don't think there are that many websites about it (really about it, not just deeplinked articles), but if there are, I think it would be closer to intentional frugality. Probably after liftarn collects the sites s/he is thinking of, it would be easier to tell.