http://optimizr.dyndns.org/dos/usbdrv.html
options 1 &2 work w/ the one System i have as a test guinneapig. the USBtoASPI driver it loads on both detect the unit just fine. the USB Mass storage Device handlerwill find it just fine and assign it a working "D:\" but complains about MBR Read Errors( pay it no mind i dont think it properly supports a LS120 just yet.) but theres 3 minor Issues to keep in mind:

1: if its not plugged in before the USB to ASPI Driver is.. your going to haveto restart
2: the LS120 Floppy must be in before boot/drivers are loaded, as swapping floppies will give it a Illegal Disk Change error that wont go away forcing a restart
3: something loading in Protected Mode. while this isnt Mainly a cause for concern, this means you cant load Windows 3.1 to see if it works as a fixed Disk.

does make transfeering data to n fro w/o having to get CD-RW or scowering for 2GB USB Flash drives, alot easier even if its just 120MB at a time.
EDIT: forgot to mention mines a version after they eliminated the Clunky SCSIto-USB Dongle connector in the back. just used a standatf IDE to USB converter internally w/ a USB-TypeA connector on the back.