You know the problem when trying to get just one file or folder out of your GIT repository? For example if you had a repository for all your Magento modules you’ve written, you might want to extract only one of them to a new project. Sure you can use subtree but sometimes you only want to get a certain version or just don’t need the GIT – stuff. In these cases you can use
$> # git archive --remote= | tar xvf - $> git archive --firstname.lastname@example.org:sheldon/ask-sheldon.com.git' master path/to/file/or/folder/in/repo | tar xvf -
to get the required files or folders out of the repository.