While reading through a discussion on Slashdot today, someone linked a thread from 1999 as proof that the Slashdot community has always been pretty dumb collectively. The thread was on the upcoming release of VMWare, a class of products that clearly hasn't been heard of on PCs at the time.
The thread can be found here. It's amazing how a concept so ingrained today appears to be so foreign just 18 years ago. My personal favorite is the very bottom comment "a great idea ROFL."