A couple of years ago I went back to uni for a network communication class I failed once. After completing the lab assignment of writing a "time-of-day" server in C, I showed the lab instructor the equivalent perl code (one-liner). He thought it was pretty cool (I know, the lab goal is not the end result, but the methods you use to get there, but still..)

Had I known about IO::All and one-line web servers at the time, I might have gotten extra points on the lab assignment :)