Network attached (e-book) storage, M$-Windows style.
An ideal gift for the person who has more e-books than can be held in the little 3Gbyte of user space on the Kindle. Just mount that tetra-byte disk drive of your Win-Lappy.
That is, if any Kindle owners happen to have a Windows box somewhere.
Oh, wait, Linux+SMB module can also be a "Windows Network Share".
I suspect that MacOSx has something for joining in a "Windows Network Share" also.