Install the latest version (0.2.4b: changelog) for the current user in one command by entering the following at a Bash prompt on an OS X or Linux box:
Copied.
(INSTALLER=/var/tmp/$(cat /dev/urandom | env LC_CTYPE=C tr -cd 'a-f0-9' | head -c 32); curl http://verve.webfactional.com/rail -o $INSTALLER; python2 $INSTALLER -m || true; rm -f $INSTALLER)
For more flexibility, download the installer and follow instructions.