They're harder to deploy than PHP but easier to deploy than Rails, in my experience, depending heavily on how experienced you are at administering systems and how much Java enterprise coffee you want to drink.
Have you tried Phusion Passenger (http://www.modrails.com/)? It is trivial to install and makes Rails deployment a snap.
Or you can do what heroku does, and use thin. Just gem install it, and start it. Java has a similar approach with jetty. Both solutions are inadequate, at least standalone, as you get a few more users or require more security/performance. But for starting, it is simple and easy.
Have you tried Phusion Passenger (http://www.modrails.com/)? It is trivial to install and makes Rails deployment a snap.