• Git 1.6+
• NFS (MacOS works OOB, on Debian based linux distributions install nfs-kernel-server package)
• Vagrant

git clone git://github.com/symfony-cmf/cmf-sandbox.git
cd cmf-sandbox/vagrant
vagrant up

Now everything is getting prepared.
In the meantime you can optionally add an entry to your /etc/hosts file like so:

172.22.22.22 cmf.lo

If you have added the entry to /etc/hosts you should be able to access the Sandbox like this:

http://cmf.lo/app_dev.php

Otherwise you can also use the IP address:

http://172.22.22.22/app_dev.php