I recently got the fancy Apple earphones for my iPhone GS. Along with the microphone, the earphones include a volume control. But wait ... there's more!!!!
In addition to volume control, you can now skip, fast forward, and rewind all from your headphones. No need to get your iPhone or iPod out of your pocket. Unfortunately, the command listing comes in a thick little booklet that contains about 20 language translations. Not very portable or useful. Therefore, I created the following english cheat sheet and posted it on this site. The page includes a link which allows you to store the cheat sheet offline in a bookmark. Enjoy!
iPhone/iPod Earphone Commands