I bought a pair of
Sennheiser PMX80 Sport II Headphones from the Apple Online Store. What I was hoping for was open-ear headphones that I could wear while riding, without the ear buds falling out of my ears. This is the major problem I have with using the iPhone while riding.
The PMX80 headphones are a hard plastic, the phones themselves are in a fixed enclosure, there are no hinges or adjustments on this product. The phones are designed to sit sideways into your ear, which presses the hard plastic against just about every surface around your ear hole. Make sure you use the supplied pads. I found that without the pads the headphones started to get quite painful after about 20 minutes. Even with the pads, the mounting bracket pushed against the back of the earhole and after an hour was becoming quite uncomfortable, then by about two hours it was almost painful.
Within a minute of wearing them I'd already discovered just how much I'd grown familiar with the Apple ear buds with their microphone and remote control - I really miss that remote, especially in the office environment. I've already hatched plans to graft the remote control and microphone from my old Apple headphones onto this set, perhaps by fitting a 3.5mm inline socket in place of the old ear buds.
Another minor niggle is that the impedance of the headphones is lower than the impedance of the Apple ear buds, so music is quite loud even at low volume settings. When sitting in the office I usually have the volume turned down to between 1-4, where with the Apple ear buds I would have the volume up around 11.
So far they fill my selection criteria - they have decent quality sound reproduction, they fit on my head when I'm wearing my bike helmet, and they're unlikely to fall out while riding (unless I'm trying very hard).
I still have to get them home and out for a ride! Watch this space for an update. My immediate concern is wind noise.
My lasting impression: What a long product name! Needs iPhone compatible remote, but otherwise wonderful for short periods.
Update: want a PMX80 headphone with iPhone controls?
The Sennheiser PMX 680i headphones will be exactly what you want!