Emboldened a talk that Ryan Senior gave at the St. Louis Lambda Lounge (now available as a video), I grabbed the most popular two Emacs versions for Mac OSX:
Aquamacs
GNU Emacs 23.1
and set up each on my Macbook Pro (10.6.2). For each Emacs, I also set up SLIME, Swank, and Clojure.
If that sounds like a bunch [...]