I have managed to "tweak" my environment so that it now downloads the pictures directly from my own flicker account. I've also managed to get it working with authentication so it can download your pictures which are marked as private.
Ok...maybe a bit like a chocolate teapot I know, as there are enough solutions on here to point to a folder instead of flickr, so why not just use that instead?....i agree, however it does have 1 added bonus.
If you create an account on Flickr and then create a group, you can link in your friends and family into that group then they can add pictures into the group folder which will then appear in your screensaver. The group folder can also be private and it will work.
Is this something the community would like? If so let me know and I will document the steps.
NB....any gurus out there know how to stop the screensaver stretching the images when it displays them?