Run php as cgi in Apache

Download and intstall apache and php, I recommend using the tarball.
I installed apache in /usr/local/apache
./configure --prefix=/usr/local/apache;make;make install
and php reside in /usr/local/php
./configure --prefix=/usr/local/php/

Now you may edit the config file for apache
vim /usr/local/apache/conf/httpd.conf

you may place your .php file inside the document root directory
for me it is index.php
DocumentRoot "/usr/local/apache/htdocs/"
Inside the Directory section of "/usr/local/apache/htdocs/"
Options ExecCGI
AddType php-script .php #make sure there's no other type defined for .php
#Instead of AddType you may use AddHandler or SetHandler whichever is appropriate. See what is the differece, here.
Action php-script "/myphp-cgi/php-cgi"
Order allow,deny
Allow from all

ScriptAlias /myphp-cgi/ "/usr/local/php/bin/" #Map your php-binary location using ScriptAlias

You have to access the file appending /index.php unless you specify it with DirectoryIndex