If you are using FlickrAPI and you are storing the photo id’s in a MySQL database, make sure the column is a bigint 
Flickr reached the integer limit (2147483647) today with this photo.
We’ve been bitten by this. We are using the Flickr API on the What’s Cookin’ website and we were using signed MySQL integers, which overflowed today.
Thanks, this tip saved me a lot of troublz!