Why not install an external USB2/Firewire Hard Drive. You can pick up a 200gb or 250gb very cheap nowdays.
If it's mainly for email storage google-mail accounts archive your old emails instead of deleting them, if you need an invite pm me.
If it's for photos etc there is a free account you can get at photobucket. [very popular]
http://photobucket.com/
Also worth a look are..
http://www.putfile.com/myfiles
and
http://imageshack.us/
http://www.34sp.com/hostingfeatures.php not free but starts around £15 or so per year.