When used as conjunctions, they're interchangeable . But you can also use "though" as an adverb at the end of the sentence: "Your cousin seems like a nice guy." "You mean Mark? He's lovely. He's not my cousin, though." You can't do this with "although", though :)

Hi again, lol Pretty much the same meaning for both; just that " though" is a little bit stronger than "although". Best, -Mike