If you try to upload a photo at the moment, you'll see this:
What's up with that?
Did you have a hard time reaching the site yesterday, last night, this morning? Me too. The culprit looks to be some huge photos that were uploaded — or rather, the way the site was handling those huge photos. So uploads are suspended until some safeguards can be put in place. Sorry about that.
Updated 6/8/2009: fixed.