As a recent convert to the iPhone and a headphone junkie, I was making due with my old earbuds and no mic, willing to sacrifice convenience for audio quality. After I stepped on and crushed my Shures, I was living with some Sennheiser CX400s while I dug around the apple site and tried to find a decent pair of headphones that could capitalize on the new inline-remote features. I was having no luck until I found these.
The audio quality on these bad boys is plenty good. Much better than the Sennheisers (which cost about the same), not as clear as the the Shures (which cost twice as much), but with a lot more bass.
The beauty of these headphones is the inline remote. It's a snap to control the volume, skip or repeat tracks, and use the phone hands-free without taking your iPhone out of your pocket. You can also use voice-commands to control other aspects of the iPod, which is cool but I've barely used it. I get self conscious standing on the train saying "Play Songs by Wayne Hancock" loudly into my sternum. The remote/mic is so lightweight I barely notice it on the cable, and I have gotten no complaints about voice quality. All in all, the cabling is pretty lightweight (and on the short side, but long enough to make it from your pocket to your head), but the earphones and joints seem sturdy enough to last for a while. There's a two-year warranty though, just in case.
Two caveats: the first pair I got was defective and almost immediately started malfunctioning. Amazon replaced them right away and the new pair has worked flawlessly. Second, I liked the included rubber sleeves but prefer foam, so I used the foam tips from my Shures, and they really make a better seal.
These are a no-brainer if you are looking for better headphones for your iPhone.
UPDATE: It looks like I wrote this review over a year ago, and these things are still going strong (the replacement pair, anyway). I use these five days a week for at least an hour or two, so there's some wear and tear: the rubber around the connections on the earphones and the plug is split, but to their credit, they still sound and work nearly flawlessly.
This isn't a new problem, but I finally put my finger on it: every now and then the buttons get switched up, and up is down and vice-versa. It's just a momentary annoyance, but I thought I'd mention it, especially in light of the fact the there's a ruggedized version of these coming out any day now, S5i. Built with a sturdier cable and a moisture-proof remote/mic, they might be the right choice if you're going to be taking these on runs or generally manhandling them a lot. Haven't seen 'em though, and these are still the champ until I do.
I have only one complaint about the design itself: the have a straight plug instead of the L-shaped type. It makes the phone/ipod seem that much taller with these plugged in, and I feel like it puts unnecessary stress on the soldering when they're yanked on.