You can do either. I tend to put my pins (I don't have a lanyard) into my carry-on because I'm a little leery of leaving something like that in checked luggage (I'm sorry to say that the stories about the less than honest luggage checkers has me worried about small easy to steal items like that). In terms of the carry-on, I tend to put everything into a ziploc baggie so that it's easier to pull out if the TSA agent asked to see into the carry-on (which happens occasionally).