It's absolutely acceptable to have a prepared list of things that you'd like to cover. As a candidate, I like to have them hand written, personally, and cross them off as we discuss them during the course of the interview.
As an interviewer, a prepared candidate makes a much better impression than an unprepared one. Walking in with a list of questions makes me think that you've actually thought about the company and the position and that you care about something.
However, if you were to bust out with your phone or a tablet, that would be a big negativenegative*. Both of those are pure distraction devices and your attention needs to be fully on the task at hand. While that might seem to be "outdated" advice, consider who you're trying to impress in the interview and recognize that they might not have the same relationship with technological gadgets that you do.
*Unless, of course, you're demonstrating an App, Website or other artifact that you've developed.