It's official

[dtm]

From the quiz solution summary on http://rubyquiz.com/quiz122.html: (ellipses in the original)

You have shown me the light and it tells me... Daniel Martin is crazy. I'll leave it to him to explain his own solution, as punishment for the time it took me to puzzle it out. I had to print that Array inside of the inject() call during each iteration to see how it built up the answer.

Update: I did in fact accept my punishment and post an explanation of my twisted implementation of the Luhn algorithm.

Update: Sorry; anonymous comments aren't shown on this entry any more. Three spam deletions is my limit.