I would say the folder route is the most effective of these solutions all round. Not only do you retain all the link equity in one place you can target the folders via webmaster tools. This is also a low cost solution that is fully scalable to very large sites (hence your apple example).

I was wondering though, what effect do you think it will have having links from different countries pointed at each folder. Do you think Google will recognize whats going on here and how do you think this will affect the rankings of any non geotargeted pages. If you are only targeting english speaking countries you would want might want to share the homepage between the countries so it can gain all the links.