quine

n. A program that generates a copy of its own source text
as its complete output. Devising the shortest
possible quine in some given programming language is a common
hackish amusement.
Here is one classic quine:<p>

&nbsp;&nbsp;&nbsp;((lambda (x)<br>
&nbsp;&nbsp;&nbsp;&nbsp;(list x (list (quote quote) x)))<br>
&nbsp;&nbsp;&nbsp;(quote <br>
&nbsp;&nbsp;&nbsp;&nbsp;(lambda (x)<br>
&nbsp;&nbsp;&nbsp;&nbsp; &nbsp; (list x (list (quote quote)
x)))))