All4Cellular via eBay offers the 5-Foot 3.5mm Male-to-Male Auxiliary Cable 2-Pack for $2.09 with free shipping. That's the lowest total price we could find for this quantity elsewhere by $2, although we saw a comparable name-brand pair for pennies less a month ago. It's compatible with any audio device with a 3.5mm stereo jack, including the iPod and iPhone.