When I try curl get.fuelphp.com/oil | sh on Linux (Archlinux update) or Mac (Mountain Lion update) it doesn't work anymore.
curl get.fuelphp.com/oil | sh
% Total % Received % Xferd Average Speed Time Time Time Current
Dload Upload Total Spent Left Speed
100 244 100 244 0 0 103 0 0:00:02 0:00:02 --:--:-- 244
Just that, see http://docs.fuelphp.com/installation/instructions.html
After you've installed the oil command 'oil create <projectname>' will download the source into a new folder (of the current directory) called <projectname>.