That's a well-known "feature". The cord of the headset is used as an antenna, but without it, the reception is quite satifying. I've never understood why Samsung enforces the headset to be connected.
The part with the wired headphone/headset is indeed well-known and quite logic ofcourse, but the stylus pen, the metallic stick (which you have slide out of the phone) does also fit in the jack, with the possibility to function as an alternative antenna.
Quite funny actually if you want to listen to the radio and forgot the headset
Also it seems to work with (some) HTC devices
Edited by Alchedin, 26 October 2011 - 09:16 AM.