It seems linksys has exactly what I was looking for at $80 (from their site):
"Link for USB 2.0 Disk Drives which connects USB 1.1 or 2.0 disk drives and flash disks directly to your network. Just plug it directly into your 10/100 Ethernet network, and attach your USB 2.0 hard drives or flash disk. It can self-configure to your network via DHCP"