on Samsung Vibrant to setup usb for OSX

• go home, then choose settings
• choose 'Applications' then 'Development' (the option just above 'USB settings' on my phone)
• check the 'USB debugging' option
• now plug in the USB cable connecting the phone and computer
• at the top the usb icon appears (pronged fork type thing) open the notifications panel and choose 'USB connected'
• choose the 'Mount' button, this should mount the device on OSX
• create a folder and copy mp3 files into it (any arrangement or naming you like)
• when finished unmount the device and the phone will then scan its media, the media player should automatically show all added mp3 files