I just pushed out my first Ruby on Rails application a few days ago, and the shakedown cruise is going well.
You can check it out at ThirtyDayList.com if you want. There are still some features I want to add and it needs to be DRY'd out, but I'm happy with it.
I used the book Rails for PHP Developers which was pretty good and brought me up to speed without much fuss.
I have to say, I'm really digging Ruby and I'm really digging Rails. It's nice to not really have to worry about all your database stuff, ActiveModel takes care of the hard parts.