Hamming distance between two words

That's...a great undergrad blog post that goes into much more detail than necessary (and juggles symbology, IMO), but if you are going to go into so much detail, why not discuss Levenshtein Distance?

Writing a little application which takes two words of equal length and prints the valid words path from one the other is a great exercise. Staring with the first word, change one letter at a time, so as to end up with a valid word in the language of choice, until you have the other word. Try turning "comic" into "flair".

This is difficult for a human to do. So do doing it code is interesting and revealing.

Pretty cool stuff. My only objection is that it's easy to explain this stuff in algebra, explaining it in plain English is a nice exercise for the reader. ;)