Belkin 5-way Headphone Splitter (3.5mm)
for iPhone 3GSWith the Belkin 5-Way Headphone Splitter you can connect up to 5 headsets to your iPhone 3GS's 3.5mm jack!
Seidio Headset Adapter (3.5mm to 2.5mm)
for iPhone 3GSThe Seidio Headset Adapter allows a traditional 2.5mm headset to be used with a device that has a a 3.5mm port.
75% Belkin Headphone Splitter Y-adapter
for iPhone 3GSThe Belkin Headphone Splitter lets you connect two stereo headphones into a single mini-stereo jack on your iPod, MP3 player, or any device with a 3.5-mm audio jack.
Incipio the OX Audio-to-Audio Jack Cable
for iPhone 3GSThe OX cable sports two 3.5mm male-to-male plugs to hook your music player up to an audio-in receiver for increased playback experience. It's as simple as plug, plug, listen!
NoiseHush AS12 3.5mm Auxiliary Cable
for iPhone 3GSThe NoiseHush AS12 3.5mm Auxiliary Cable allows a direct connection between your mobile/smartphone, MP3 and DVD players to any car or home stereo equipped with a 3.5mm port input.