The widget that you are looking at on Ebay is not a generic adaptor it is a specific networking device. If you plug one of these into an XP PC it will raise a flag to the OS that it is a network adaptor (LAN Port). (rather than a generic RJ45 to USB)
EG if you plug the RJ45 end into any device, with the expectation of converting it into a general purpose USB port, you will be disappointed.
Its main purpose is to allow devices such as printers that only have USB ports to attach to a LAN and be shared on a network
Most USB to whatever adaptors are actually intelligent devices with an embedded chip that is programmed to do specific tasks.
So, in answer to your first question, NO.
most folks use the LAN (or a direct cable to another PC) in network mode to give the dreambox STB (500 models) access to a hard drive, rather than hanging a hard drive directly on the STB and getting to it act as local storage.
Basically you get the dreambox talking to the rest of your network, then set up a hard drive inside a PC and allow the dreambox to use this hard drive.
I'll not go into any details here as it is already documented in several places on this and other forums.
Good Luck
