Originally posted on February 1, 2006, our review has been updated on June 21, 2007 with new iPhone-specific details. We preserve the text of our original review for your reference; the updated section is found at the bottom of the page. In recent months, we’ve had only occasional need to look at headphone splitters - inexpensive accessories designed to turn one headphone port into two, enabling two people to enjoy an iPod’s music at once.…