Just edited my post, while you were writing.
Look at the additional info!
Well,... I have it connected to my router, because I also use it for PC-related stuff, but yes... It should be quite possible to attach it directly (I presume you need a Crossover-Cable in most cases.).
Btw.: If you already have a Router with USB-Connections, you might not need a NAS at all.
Do you happen to have a router with USB-Connections?
PS2 V7/DMS3 V2 (FW:2.4b7); Seagate Baracuda 200GB
PS2 V7/CC1.0 (FW:34 hacked v2 BM:2.1.6); Maxtor DiamondMAX9 PLUS 160GB
PS2 SCPH-30004R; NoMod+NoLaser
3xSony MC 8MB
MAX/Datel 16MB with Boot-CD
Custom FMCB 1.8b+ Beta-Build, my AIO 0.5, Sony&xRhino-Linux