Sam, I use both. I'm in the process of designing a small note book that I can carry around with me. What I do currently is wake up in the middle of the night, put the title in an email and send it to me so that it is there in the morning.

Every writer needs to keep a notebook or have a place when ideas pop into their mind. It truly doesn't matter how experienced you are. These things are there for a moment, and then something comes along, and one cannot remember them. There have been so many times that I could have kicked myself for not writing them down. I knew I had something good, then didn't write it down, and then it's gone for good.