Virtural Host with Apache + FastCGI + RoR

First question:

FastCgiServer /users/foo/rails/public/dispatch.fcgi -initial-env
RAILS_ENV=production
Do I need define this for every vhost,
or just only one in httpd.conf?
If I need to define it once, what should be the path?
I am confused as I have dispatch.fcgi in each of the public direcotry
of my vhosts.

Second question:

Can I run 2 of my vost in development envionment, 1 in test envionment
and another 2 in production environment?
If so, how?

Thanks,