Not sure why none of these are marked as the correct answer, but I landed here through a google search, so I will pass along what I know...
@paul_g's method was pretty close for me, my steps on a Mac osx10.9 Retina:
--insecure
flag for SSL related issues) $\curl -sSL --insecure https://get.rvm.io | bash -s stable --ruby
rvm requirements --with-gcc=clang
You won't have to update Ruby because you downloaded the last stable versiongem install compass --pre