I have a Rails 3 app ready for staging.
I haven\'t got a VPS host set up yet. As I was planning to have everything on shared host for the first few months.
The solution is here http://rvm.beginrescueend.com/integration/passenger/. You need to point your HTTP server to passenger_ruby wrapper instead of bin/ruby.
E.g. for RVM & Apache it should be something like that:
PassengerRuby /Users/username/.rvm/bin/passenger_ruby