rolled up and rubber band cable. On my head on the go out into my bag when I want. Really why I said perfect portable is because they are as durable as the m100, but actually sound better. They don't make your ears sweat, they are more comfy then most. They are lightweight not to big strong cable also. They may not be as small as the many smaller phones people class as portable but find me a headphone that sounds as good, doesn't make you sweat and is light and durable with a tough cord that can take a beating.
Well hopefully these MDR 1Rs that I ordered sounds as good, because in all other areas, it either beats or is equal to.
Also, and I hate to say it, but a tiny bit sound quality is and IMO should be sacrificed for the sake of convenience and portability. It's great that you think they're good for portable use. I'll compare my experiences when I get my 1Rs.