Ok, so I thought I'd go through the Zen Framework Quickstart Tutorial here...
http://framework.zend.com/manual/en/learning.quickstart.intro.html
I created a project, a virtual host, and a layout. However when I got to the bottom of the instructions here:
http://framework.zend.com/manual/en/learning.quickstart.create-layout.html
...my layout didn't show up. Looking through the comments at the bottom of the page I saw that some other people where having the same problem. There wasn't an obvious fix though. I decided to press on and revisit the layout. So I created a model, a DB table, and a controller. Everything seemed to be going smoothly until I got to the checkpoint at the end. When I went to http://localhost/guestbook I got a 404 error. Again some other people seemed to have this problem but the only fix suggested didn't work.
Anyone have ideas?