I used to do it occasionally on shorter rides when I knew I wouldn't lose a station or reception, but with the advent of portable satellite radio and high quality noise-reduction earbuds I rarely leave home without them. With over a 100+ stations of music, sports, and talk to choose from I doubt I could ever be talked out of riding without them. I also enjoy not having to listen to vehicular traffic. After more than 6000 miles of riding with no incidents no one is going to convince me its more dangerous. The few times in the past I got brushed and planted(all without listening to a radio) was either done on purpose by a motorist or my own poor judgement. Exceptions are congested riding areas and group rides in which I never listen to a raido. I also would not recommend them for riders who don't ride 110% defensively and respect the motorist. Being able to hear a motorist that your pissing off by your erratic or "I own the road ridng" may save your life. The very fact that I'm shutting off the external environment forces me to be a safer and more conscientious rider. As far as the rare rider who think's I'm hindering their ability to organize themselves for the last 1000 m of sprint that only exists in their head, I could really care less.