It's not too often that you'll have a server that runs two applications. Sure, if that were the case then you would be using RVM in which case I would recommend

It's not too often that you'll have a server that runs two applications. Sure, if that were the case then you would be using RVM in which case I would recommend following the guide already linked. But if you've got one application running one version of Ruby, then this is definitely a perfect way to go.