this is a gitignore from a relatively large Rails 3.2 app (created with Rails 3.1)
/.bundle
/db/*.sqlite3
/log/*.log
/tmp
config/database.yml
config/google_analytics.yml
.DS_Store
/nbproject/
public/assets/**
just the basic gitignore which comes with rails and added some developer specific stuff like Netbeans project stuff, the .DS_Store from OS X
and we don't like passwords in our repository, so we add all yml files with passwords to gitignore
we also added public/assets/** since we deploy our apps with capistrano and generate the assets during the deploy and push them to amazon
.gitignore
file for you with the most common non-source-control files included already – Jug