This little device caught my eye when scanning through a suppliers newsletter. Just add a hard drive to it (up to 250GB) and you have a file server with all the features you need for many small business networks.
It is based on an embedded build of Linux and is administered through your web browser interface. As CIFS/SBM is supported (probably using Samba) you can use it with your Windows machines with next to no configuration.
More information is available from the Lindy web site at http://www.lindy.com/uk/productfolder/03/32/32454/index.php.