Hi.
I have used this kind of NAS during last 6 months: LaCie Ethernet Disk mini
Gigabit Ethernet & Hi-Speed USB 2.0. It is quite cheap and reliable ( now it have uptime ~ 4 months, no reboots or anything else needed). It is very easy to configure (web interface) and because it has own uPNP server Canola and Media streamer find it directly when uPNP server is on.

Hannu