Dave, does this keep them private? I noticed with photo bucket that you lose a lot of image quality.
G, if you are wanting to keep them accessible on the cloud. Start an album in shared but don't invite anybody to it, just upload all your photo stream to it. I'm not sure if this will work once you delete the photos, however i'd test it with a single photo. When I get a minute later tonight I will have a play with it to see if this works.