Updating rails should have been easy as ruby and rails are included in Leopard. I should have only had to do
sudo gem update --include-dependencies
And then it would all be right as rain. However, as Rails has recently made some big changes, and changed its gem repository from rubyforge to http://gems.rubyonrails.org, I needed to fix a few other issues too, and add in some more gems to make it all happy. Thanks to the details at the google group for rubyonrails, and the note to add in the gem update for rack (yes, rack, not rake), all is happy and I’m now at rails 2.3.0. Ok, still need to do mysql.