My own teaching is 'blended learning'. Students have a mix of online material, text books, face to face and online tutorials and opportunities to chat in forum posting. About 80% of the material is online and I work hard to get my students to go online.
Recently a friend came to me with the opposite problem.
I used to teach in traditional universities too, so I felt considerable sympathy with my pal. He teaches Physics in the States, and his students sit in the back row, checking out Facebook and even chatting on their mobile phones. A colleague of his had passed some handy research papers his way which showed that 'multi-tasking' leads to poor grades, as the researchers politely call it - or rudely 'phubbing' your lecturer in spite of their efforts to raise your grade and improve your academic knowledge, as my friend might call it. (I used other language on the one occasion this happened to me.)
Useful though it was to definitively know this, and it was great fun to cite a paper called No A 4 U, my friend was in need of a practical means of getting his students to stop checking their phones and pay attention to him.
Should he make an impassioned 10 minute plea to the students - referencing this and other studies which evidence the grave consequences of their careless phone habits?
Should he institute a confiscation policy and take phones away at the door?
In one lecture series I taught, I used to put a slide up at the start of the lecture with some relevant information on it. Keen early bird students could read this/watch the video clip/listen while the others shuffled in and found a seat.
I started the lecture series with Lily Allen's F**k You. I explained that Ms Allen is in a tradition of song-writing including 2 Tone, in which efforts were made by song-writers to transcend skinhead racism of the time. I hoped that would gain the students' attention, and help them understand that 'Race and Ethnicity' is not just some dry dusty academic subject.
I suggested my friend imitate this tactic. He could just put up a slide with the relevant advice on it for his students. He could leave it up for 5 minutes while they settled in their seats, then put up his lecture slides and teach as normal.
My friend loved the idea and gave me permission to share the slide I threw together for him:
PS In response to a helpful suggestion from Simon Reed in the comments, I've attached a new version of the powerpoint slide. It has a video from YouTube embedded in it showing what may happen to you if you use your mobile phone in some lecturers' classes ...