Looks like a BT Home Hub... phone (voIP) and WiFi IIRC.
100% correct. It's my wireless router and VoIP phone that it came with. Streams wireless to the MacBook and a 24"iMac in the lounge as well as my girlfriend's iBook.
The cube and the iMac G5 run off ethernet into the back of that hub. The aerials for EyeTV are hidden rather well as are many of the cables.
It's all hooked up to a huge AMP underneath my desk which in turn connects to two huge black speakers - the top of one being just to the left of the iMac, next to the LaCie drive.