While we're sharing fun information, I'd like to point out a little-used feature of Markdown syntax: if you put four spaces before a line, it's treated as code. Behold:

(define (make-counter)
(let ([internal-variable 0])
(lambda ()
(begin (set! internal-variable (+ internal-variable 1))
internal-variable))))

Also, the emacs rectangle editing functions are good for this. C-x r t is a godsend.