I’ve started doing long solo rides in preparation for some cyclocross races in the Autumn. When I was racing on the road in the 80s and 90s, I often did huge solo rides with a walkman, so ipods are a nice change from their bulkiness. There are some safety precautions that one can take, however:
#1. Only use these devises when riding solo. They are a tremendous distraction during group rides, even with just a few people, and group rides are for chatting and socializing with friends, right? The only time you should wear an ipod on a group ride is if you are riding with people you don't like and/or trigeeks. You may want to drown out their ridiculous banter. Also, if they do deign to ask you a question, every answer will be a bizarre non-sequiter since you won’t know what the heck they are talking about.
#2. Wear just one earpiece, preferably in the right ear, and keep the volume at levels that aren’t distracting. Use the smaller “ear plug” type earphones. The bulky disc earphones will negate the use of a helmet and are guaranteed to make you look profoundly retarded.
#3. Refrain from listening to anything by Joanna Newsome or Devandra Bernhardt (or any of these other new neo-folk artists) as all of these can cause various levels of dangerous distraction and confusion to the listener that can leave you dry-heaving in a ditch.
#4. Remember—you will look even more Pro and Euro if you have an earpiece dangling from your ear.