In reply to Dominion:
> I would assume that both python and curl are installed on OS X by default, as it's a *nix (BSD) based OS, but I don't know this, 'cos I barely use OS X.
>
> Although I do have a Mac Mini that I could power up and see.
Well, I downloaded the installer using the instructions on that page, onto my Mac Mini, and ran
sudo python install.py
and if I'd had an SDCard reader / writer in my Mac it would have worked.
After you do this first bit - which creates a small boot partition on the sdcard and puts a few files on it - all you do is put the sdcard into the Raspberry Pi, and connect that with an ethernet cable to your network, so it has internet access, and it downloads all the rest as it boots up.