My idiot hosting company seems to have made it impossible for PHP to write session files to /tmp, making some code that’s been running nicely for years suddenly start to throw error messages wherever it dares to use session variables (not that I would! it’s a third-party Flickr library). Nice job, guys. A pissy ticket has been filed with their help desk, some error-suppressing @’s have been added to the code, and hopefully the issue will be resolved shortly.
UPDATE: All better. And hey, a new header image to celebrate, courtesy of this CC Flickr image.