To use this tool, simply download it from the below location, decompress it and use dd to place it onto your USB Key. If you are not familiar with the dd syntax it's quite simple really; dd if=/path/to/extracted/hex-i386-1.0.1.usb.img of=/dev/da0 (your USB device). Note, that you should not dd this to a mounted partition, it will not work. You need to dd onto a USB Key that you don't mind losing the data on, because this will overwrite everything on that key. You can create a small partition after the dd (this of course assumes that you know how to do this, leaving the existing partition in-place) and have that to write data to etc...
This image does require a minimum 2G key (actually uses 1.75G), and has no minimum memory requirements (other than standard fbsd and X requirements).
MD5 (hex-i386-1.0.1.usb.img.gz) = cd7489ba0a2a1fe824d286c72eee6842
SHA256 (hex-i386-1.0.1.usb.img.gz) = ffbb428145e0184d3848e45afee0d10ba41a4d9177688db10befc943dd4058f5
Please test this out and let me know how it works for you, or let the entire team at rawpacket.org know.