When a group of girls (i.e. slam pieces) convene to take pictures of themselves in PhotoBooth or any similar application. They may also gossip or discuss their menstrual cycles. The opposite of a Brovention.
While the great thinkers of ancient Greece held symposiums to discuss philosophical quandaries, Amy held a Slamposium when she got her braces off.
When you get slammed (hammered, drunk, ect...), and also get some "poon". The phrase is growing in DMV area universities, and has even been heard in Carolina schools.
Jacob: Who's ready to get SLAMPOONED?
Todd: I'm already slammed, so we just need some poon