While surfing the net I found an interesting little program

called ‘GMail Drive’.  This nifty little Windows shell extension

will allow you to use your 2GB gmail account to be used as storage.  Files are basically added to your account in

the form of an email with the file attached; you can access the files as you

would with any other network drive, it integrates the storage with windows

explorer.  The web address is http://www.viksoe.dk/code/gmail.htm

Actually it reminded me of a similar project I saw a while back

called GMailFS, this allowed you to mount your gmail account as a linux filesystem.  After a quick google search I found this

projects homepage

and it seems that it is still being actively maintained.

I’m sure neither are very secure, reliable or practical;
still they are a novel use of the free storage being offered to users.