As you may remember, I had some ear troubles earlier this year that resulted in getting some sweet custom made earplugs. These have been a boon in numerous situations (e.g. vacuuming, mowing the lawn), though I can't say I've used them for anything involving music (they are "musician's earplugs").
The earplugs are especially good on an airplane. The ambient noise on a plane is not messing around. Have you ever noticed how high you have to turn up your headphones in order to surmount the plane noise? Yeah, that's bad for your ears. Mark my words, there is going to be an epidemic of hearing loss in like 20 years thanks to crappy earbuds and the explosion of personal music/multimedia devices.
So what is the paranoid ear freak to do when there are in-flight movies to be watched? Acquire some sound-canceling headphones OR in-ear earphones and outfit them with Comply foam tips! I bought these Altec Lansing UHP336 earphones for cheap at Amazon before our summer Eurotrip. I'm not an audiophile--I mean, I like sound but I'm not a nerd about it--and didn't do much research, but these were a good deal and had tons of helpful reviews. As recommended by the nerdy, helpful reviews, I replaced the included earphone tips with the ones by Comply--they're memory foam. They conform to your ear canal and isolate the sounds you want to hear while blocking out the sounds you don't. Pros: the volume setting on your pod/whatever will be minimal and you'll be amazed. Even Ira Glass's mumbling at infuriatingly inconsistent sound levels will be clear and intelligible. Cons: the foam tips need to be replaced regularly, because your ear canal ain't pristine. Also, you won't want to wear these when it's important that you be able to hear what's going on around you, e.g. when you're walking alone down a dark alley.
Every time I take the phones out, I'm amazed by how much outside noise I've not been hearing. Really! Riding the bus is a much more pleasant experience this way.
Now if I can just find some non-nerdy safety gear to wear while biking in the dark, I'll be all set. There's totally a market for this, right? I keep thinking that would be a good Etsy shop idea, if only I could sew properly.