The following iPod music remote just came in the mail today:
http://www.dealextreme.com/details.dx/sku.84
It was so cheap, I was willing to risk trying it to see if it works with the iPhone. I'm happy to report that it does! The headphone cable requires a snug push, but it fits just fine in the headphone port of the iPhone (without an adapter), since the remote has its own headphone jack, this accessory doubles as a headphone jack adapter too.
All functions work great, even while the iPhone is locked (remote has it's own lock switch too). While the iPhone is locked, and not playing music with the screen off, the play button on the remote turns on the screen, plays the current music selection, and shows the current album art, before timing back out, and turning off the screen. Music continues to play, the remote allows you to pause, play, control the volume, and navigate to next/previous songs in the selection.
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On a side note, I ordered one of the
FM radio remotes too, to try it out, it does NOT work on the iPhone.