If the rumors are true, and the smartphones of the future are going headphone-jack-free, then you'll want to invest in a good pair of wireless buds. The Bose Soundsport ($149) are on the bulky side, but provide a strong, steady Bluetooth connection to your phone whether you're walking or running.
Maintained a strong connection; Good in-line controls; Works with Siri and Google Now
Bulky; App doesn't add much value