The Gadgeteer have posted a couple of iPhone headset reviews:

“Audio quality with this headset is very good for both music and calls. I was very happy using it for both tasks. People on the other end of my calls commented on how clear I sounded. Listening to to music was enjoyable as well. Compared with the stock Apple buds, I would give the nod to the iP-HS1's for both telephony and music.”

“How do the FMJI's sound? Well, for making and receiving calls, they were fantastic. For music, I found that I did not require the volume to be set nearly as high as when using the stock buds. The first thing I really noticed was how thumpy bass lines were. With some songs, this was great, but with other songs, the bass was muddy and overpowering. I listened to various styles of music with these earbuds and noticed mixed results.”