In case you're not on the Flickr API mailing list, some people are seeing a "Filesize 0" error when trying to upload photos. Apparently all calls from a specific python wrapper are failing. A few minutes ago, I tested uploading a photo with phpFlickr and I didn't see a problem, but I thought I would put this up here before I got inundated with emails from people having this problem. The Flickr team is working on it and I'm sure they'll have it fixed as soon as possible.