We still use them at work as key disks for copy protected software. New versions now have web-based activations, but there still are many cases where we need to use the older software.
And right above my computer I still have disk boxes full of 5 1/4 and 3 1/2 floppies with DOS based games :) Most of the good games were backed up to CDs, but I couldn't afford to do all of them when CDs were $8 each...