Many courthouses, but certainly not all, have relaxed the rules for attorneys bringing cell phones and other technologies into the courthouse. These days, most attorneys keep their calendar on their cell phone or tablet, in addition to notes, case law, and other essentials for a courtroom practice.

Keep in mind that individual judges often set their own policy for use of technology within their particular courtroom, even if the courthouse does not have a blanket prohibition. It is always a best practice to ask the judge for permission to use any technological equipment at the beginning of the case. I have never heard a judge deny a request, and the request itself conveys a level of respect that a judge will appreciate.