I had never heard of David Foster Wallace before this. Thanks for sharing it, has really made my day.
http://harpers.org/media/pdf/dfw/HarpersMagazine-1996-01-000...
I'm halfway through Infinite Jest right now (putting me many weeks behind http://infinitesummer.org, and I recommend it as well.
Another great one (from "Consider The Lobster"), if you're interested in linguistics and who gets to decide what is "acceptable" English, is here: http://instruct.westvalley.edu/lafave/DFW_present_tense.html (Extremely long -- if any of the shorter pieces really grab you, you really should just go to Amazon and snag both nonfiction collections.)