Okay, so I was following the instructions on the Gentoo Linux LiveUSB how-to and it told me to execute
dd if=/usr/share/syslinux/mbr.bin of=/dev/sdc

(I changed share to lib when I did this because that's where I found syslinux, but this isn't particularly relevant)

My flash drive is actually /dev/sdb1 but I forgot to change that around at the time. It apparently copied it successfully, giving me this message:
0+1 records in
0+1 records out
440 bytes (440 B) copied, 0.0297745 s, 14.8 kB/s
So what exactly did I just do, and is it bad?
fdisk -l tells me that there is no /dev/sdc