How to start your rails application via JailShell on a shared host


I'm having some troubles getting my rails application up and running
on my shared host.
As I'm using Rails 3, I believe I can't start the rails application
via CPanel -> Ruby on Rails -> Run (because this works with Mongrel
and Mongrel doesn't support Rails 3 (yet?))

So I asked my host to give me SSH access (Jailshell) and install the
gem unicorn. (which does support Rails 3 if i'm not mistaken :p)
I managed to start the server (with Unicorn) in jailshell and my rails
application works when I go to it in my browser.

But now, when I exit Jailshell, my rails application goes offline as
well. How can I start the server in Jailshell, close Jailshell and
still be able to visit my website? Or isn't this possible?

Thanks in advance,