Real Photo Sunday. An oft derided semi-tradition that many uses hate (including Rob - he even added the message 'RPS is shit, give it up' as one of the random messages in the 'post new message' page).
RPS led to a lot of people posting HUGE images on Sundays and a lot of unhappy b3tans. Is often used as an amusing reply to a really well photoshopped picture.
RPS is shit, give it up