On the ServerGrove blog there's a recent post looking at an interesting combination of technologies that could allow you to deploy your Symfony applications easier and more quickly - Capifony (Symfony+Git+Capistrano).
Deploying applications to production/live servers is always a delicate task. The whole process needs to be quick to minimize downtime. Automating the deployment process helps running repetitive tasks minimizing the possibility human error. It is also a good idea to have a proven and easy way to rollback to a previous version if something goes wrong. Capistrano and more specifically Capifony can help with the automatic deployment of symfony projects.
They start by introducing Capistrano - what it can do and what its for - before getting into some of the details like its commands and how Capifony fits in. They walk you through a sample project to give you an idea of how things are structured and the steps you'd need to take to get your project rolling.