Two excellent looking frameworks exist for web development in PHP.

Cake This project is Exactly rails in php. They simply do everything the way rails does as much as possible. I did a tiny tutorial and its nice in that it minimizes how much new stuff has to be learned.

Symfony This project appears to be very l33t. More powerful, more advanced. Its got a very indepth book to go with it. It installs via PEAR. Im going to do a hello world and see what its like.

I need to pick one for a stephouse ecommerce site that is just beginning.