It seems being creative and using a Filofax seem to go together. Nan recently highlighted Sara's Creations.
Tonight I discovered someone who makes their own organisers. Take a look for yourself at the Crafty Corner Blog and particularly at two recent posts:
fILOFAX blog and then look at the Duplex page, sorry I'm not sure what language the site is in, but there are some interesting insights to old products there.