Noise canceling headphones - life saver for travelers?

I love listening to music. I am a fan of variety, but lean more towards rock. One of the best inventions in the 20th century I believe is the personal music player. With these 'magical' devices you can plug in and tune out anywhere. I especially have great appreciation for having these great gadgets on my commute to and from work and at work. Music just makes the day go faster and most importantly helps you immerse in your own world and your work.
To make that even easier, we now have noise cancelling headphones, which not only transmit clear sound of music, but also mute the sound around you.
Sometimes all you want is a little peace and quiet, or just tune out all the things going on around you. And that is when noise canceling headphones are life enhancers, if not life saver in some situations.
Moreover, a lot of the times when trying to cut out some of the background noise, a few people, self including, have turned up the value on their speakers to drown it out. Not the best idea as it fatigues your ears and not to mention causing hearing loss and unpleasant drumming on the ceiling from the neighbors. With noise canceling headphones, such as Ultimate Ears, it would be turning down the volume and at the same time tuning out. Maybe, just maybe, all those folks on the train that have music blasting so loud in the ears that others can hear every beat of the song they are listening to, would be able to also turn it down a notch if they had the IECs.
Sennheiser and Shure are considered the kings but Skull Candy makes some great headphones also, and often cheaper ones. For full-sized headphones Sony, Bose and Sennheiser are the recommended brands.
I prefer in-ear-canal headphones. IECs provide comparable noise protection as traditional active noise canceling headphones. They're much more portable and require no extra power, such as batteries, which large noise canceling headphones require. And, in my opinion, they look better when walking around outside and easier to wear.

What others say:
- "I always listen to music while traveling. It is the best thing to keep me busy while having a boring journey. I love music and I can hardly spend time without listening to music. My cell has about 100 songs and there is the FM.So between them I listen whichever song I like."
- "I actually find music very relaxing and sometimes it helps me concentrate more at what I am doing. I guess it varies from person to person. I can listen to music all day and do many things at once and Im not affected. Some people I know actually get mad when there is other noise around them when they are trying to do something. When i am in my car I usually listen to my music pretty loud and it helps keep me alert when I wake up early to drive to school and then later on if Im driving at night."

What kind of headphone do you prefer? How do you tune out?