OK, it's a switch (which means it's like a hub, but allows a mixture of 10MB, 100MB and 1GB connections without slowing anything down).
It's small, neat, needs no configuration. I upgraded to a 1GB switch as I'm now using a network attached RAID system for storage of photographs. moving gigabytes of data around at 100MB gets tedious (and almost comatose over wireless LAN 802.11g), so the 1GB network upgrade was a must. As a result it's better performance than using a USB 2 drive.
Connects to my router, wireless access points and computers no problem. Runs a little warm, but having used it for four months so far, I've had no problems at all. It's never locked up or anything in that time.