lsusb;
Bus 001 Device 018: ID 0471:1137 Philips

dmesg;
usb 1-2: new full speed USB device using uhci_hcd and address 17
Initializing USB Mass Storage driver...
usbcore: registered new driver usb-storage
USB Mass Storage support registered.
usb 1-2: new full speed USB device using uhci_hcd and address 18
scsi1 : SCSI emulation for USB Mass Storage devices
usb-storage: device found at 18
usb-storage: waiting for device to settle before scanning
Vendor: Philips Model: MassStorage-Disc Rev:
Type: Direct-Access ANSI SCSI revision: 00
SCSI device sda: 3939265 512-byte hdwr sectors (2017 MB)
sda: Write Protect is off
sda: Mode Sense: 45 00 00 08
sda: assuming drive cache: write through
/dev/scsi/host1/bus0/target0/lun0: p1
Attached scsi removable disk sda at scsi1, channel 0, id 0, lun 0
usb-storage: device scan complete

Easy to setup, just mount it like any other MP3 Player, USB Flash, etc. mount /dev/sda1 -t vfat /mnt/gogear
However the GoGear indexes its music in a SQL database (MyDb) so you'll require openGoGear.

Download, extract, compile http://sarovar.org/download.php/516/openGogear-0.01.tar.bz2
You'll also need SQLite and ID3Lib (I just pacman'd them).

Plug-in your GoGear and wait around 3seconds for the usb-storage module to scan the drive and issue the mount command (above).
Then copy your music over to /mnt/gogear/_system/media/audio (as root, unless you mount it with u/gid=xxxx) and run gogear_flush /mnt/gogear/_system/media/audo/MyDb to empty the Db (DO NOT delete the database file, you wont be able to add any music then [blank file; http://70.85.164.146/MyDB]).
Then type gogear /mnt/gogear/_system/media/audio/MyDb /mnt/gogear/_system/media/audio/*.* to update the MyDb file, once complete type umount /mnt/gogear && rmmod usb-storage and disconnect your device!

If you don't umount and rmmod, next time you connect your device it will turn it self off, not sure why...