I was on a Ryanair flight a couple of years ago (Liverpool / Nimes). Three guys across the isle to me where talking continously during the pre-takeoff safety briefing. The young cabin steward doing the briefing stopped, "please may I have the full and undivided attention of all passengers including those who have heard it all before, until I do this aircraft will be going nowhere". Que sheepish looks from the ignorant offenders and applause from everyone else. Well done Ryanair.