Fantastic examples! I would also add möbius strips, toroidal spaces, and of course, the venerated circle. Sorry, my thoughts above are poorly worded. Perhaps what I am trying to say is that cycles should be created with intentionality, instead of willy nilly spilled throughout your code base. My complaint is really with all the mad spills of Java that I created when I thought that GC was some magic wand that freed me from having to consider the structure of the memory I was manipulating.

Someone should go around sabotaging regular expression parsers and replacing them with PEGs:

http://en.wikipedia.org/wiki/Parsing_expression_grammar

It is a crime against honest words to try to cram so much logic into so few characters.

I once was told that regular expressions were originally designed for creating AIs. The image I have in my mind is that of graduate students in a dungeon somewhere banging on type writers creating some sort of God box.

Maybe if we get rid of regular expressions we'll have one fewer problem. :-)