Amazon S3
We have uploaded a new version today - the major change is that all photos (both travel guide ones and your profile photos) are now stored in Amazon S3. It was rather easy to move our photos to them (well, Guy did it, so for me it was really easy). S3 saves us all sorts of worries (disk space, backups, server I/O and CPU issues) - and the cost is okay too. Good on you Amazon!