Fantastic bit of kit - I bought this a month ago when it was £140 and its well worth a look. This is the cheapest I have ever seen this device. You also get a free 500gb hard drive (via redemption) until the end of the year.
Same price at eBuyer (until Nov 30th) if you prefer to get there.
Stuff from Amazon description:
The ReadyNAS Duo is perfect for homes with more than one computer. Unlike a USB drive, the ReadyNAS connects to the network and is simultaneously accessible via all connected Windows or Macintosh computers. If there is a broadband Internet connection and a home router, the ReadyNAS can be set up to provide secure access to all the stored files remotely via the Internet.For added protection of stored data, an optional second hard disk drive can be installed. The spare hard drive will keep an extra copy of all the data and instantly take over if the first hard drive should fail. Advanced media streaming support allows the ReadyNAS to directly serve media, with no PC required. Officially licensed BitTorrent client allows downloading to occur without the need for an additional computer. A web-based interface facilitates download management from computers, and a special NETGEAR digital entertainer interface allows management from the select NETGEAR device.