Fastmac today announced a 3-in-1 Universal Headphone Adapter for iPhone that allows any headset with standard 3.5mm plug to work with the recessed headphone jack in Apple’s 1st Generation iPhones. The new Universal Headphone Adapter features an in-line microphone, adjustable volume slider and music/phone playback control buttons similar to the headphone capsule that ship with each iPhone. Fastmac’s Universal Headphone Adapter for iPhone (compatible with all iPhones and iPods, including the iPod touch) is available now for a special introductory price of US$19.95. Each adapter carries a 1-year warranty and a 30-day money back guarantee .