Googling turns up a few lisp-in-python implementations: <a href="http://www.biostat.wisc.edu/~annis/creations/PyLisp/">Pylisp</a>, <a href="http://www.xs4all.nl/~yduppen/site/psyche.html">psyche</a> and <a href="http://hkn.eecs.berkeley.edu/~dyoo/python/pyscheme/">pyscheme</a> (the last two being scheme, obviously). Haven't tried using them; maybe I will the next time I feel like frittering away a couple of hours.