Talking of other CS "bugs" that have turned into features, anyone who's never seen "surfing" should check that out.

Basically, you take the same air-strafing principles from this article, add a little bunny-hopping, and another "feature" of counterstrike where if you land on a steep enough slope you won't take falling damage or apply friction. Give this to some insane map makers and the end result is an incredibly skill-intensive obstacle course of sorts at tremendously high speeds.

Here's a good example of what I'm talking about: https://www.youtube.com/watch?v=o0Xv00yJhjs

There's a really dedicated community behind this stuff, you can find 64-man servers full of people playing this type of map in CS:GO and CS:Source.