Assuming you have a plugin you are developing on your computer, rather than having to push it all the way up to Github or another cloud repo, you can just clone by file path:
phonegap local plugin add /Users/yourUser/some/path
Assuming you have a plugin you are developing on your computer, rather than having to push it all the way up to Github or another cloud repo, you can just clone by file path:
phonegap local plugin add /Users/yourUser/some/path