Best riding headphones I've ever tried. and I tried them all, including the more expensive skull candies. They sound good enough and most importantly stay in place when the trails get sketchy.
$15 plus shipping from staples.com
http://www.staples.com/office/supplies/p1_Skullcandy-trade-CHOPS-Earbuds-Black_248929_Business_Supplies_10051_SEARCHNew for 2008, the Chops hanger anchors ear buds to your skull in much the same way that unruly pork chop-style sideburns help secure an unprecedented volume of YouTube filming during your synchronized swimming routine.
* 15mm speaker
* Frequency range: 18 - 20,000 Hz
* Impedance: 32 ohms
* Max input power: 30mW
* Cable type: OFC
* Cable length: 1.2 M
* Plug type: 3.5mm gold plated