On the CLISP homepage there are instructions on how to install CLISP using MacPorts and Fink, however there is now another package manager option that is quite good and gaining popularity. It is Homebrew.
For those with Homebrew installed, they can install CLISP by typing the following at the terminal command prompt:
$ brew install lisp
http://mxcl.github.com/homebrew/
https://github.com/mxcl/homebrew
thanks