Create an account at http://openshift.redhat.com/
Create a ruby-1.8 application
rhc app create -a showoff -t ruby-1.8
Then add this repo
cd showoff
git remote add upstream -m master git://github.com/richardfontana/showoff-openshift-quickstart.git
git pull -s recursive -X theirs upstream master
Add your showoff files
Then push the repo upstream
git push
You can now view your presentation at:
http://showoff-$yournamespace.rhcloud.com