Can't fix "No input file specified." with php-fastcgi

[loganbest]

I'm not sure what the standard practices of nginx+php are. This is my
first time working with nginx and I didn't install nginx, I just
installed fastcgi based on an article I found at the top of google. I've
seen php-fpm and php-fastcgi and I don't know the differences or
pro/cons of each. I'm really just looking for some quick help to get
this running. I'd also rather not have both nginx and apache running on
the same server since this isn't a very large ec2 instance I can't take
the memory footprint of apache.

Posted at Nginx Forum: http://forum.nginx.org/read.php?2,214746,214748#msg-214748