Devlin Daley gave a presentation in our 601R class on Rails so that we could discuss frameworks and the choices Rails had made. While he was talking, I poked around a little since I wanted to get Rails going on my Powerbook and found this great little tutorial on getting Rails working on Mac OS X (Tiger).
The tutorial walks you through setting Rails up with SQLite and creating a simple application. I only ran into two problems with the tutorial as written. First, when you load the Ruby Gem for SQLite, it says to type:
sudo gem install sqlite3
In fact, this returns an error. You need to type:
sudo gem install sqlite3-ruby
Second, after you create the sqlite database, you need to set its permission so that the Web server can get to it:
chmod 666 addressbook.db
I like that this uses SQLite since it's already installed on Tiger and easy to get going. SQLite is great for just exploring. I also like that it uses Apache since I'm very familiar with it.