While CakePHP is built to work with mod_rewrite out of the box, we've noticed that a few users struggle with getting everything to play nicely on their systems. Here are a few things you might try to get it running correctly:
Make sure that an .htaccess override is allowed: in your httpd.conf, you should have a section that defines a section for each Directory on your server. Make sure the AllowOverride is set to All for the correct Directory.
Make sure you are editing the system httpd.conf rather that a user- or site-specific httpd.conf.
For some reason or another, you might have obtained a copy of CakePHP without the needed .htaccess files. This sometimes happens because some operating systems treat files that start with '.' as hidden, and don't copy them. Make sure your copy of CakePHP is from the downloads section of the site or our SVN repository.
Make sure you are loading up mod_rewrite correctly! You should see something like LoadModule rewrite_module libexec/httpd/mod_rewrite.so and AddModule mod_rewrite.c in your httpd.conf.