Beer pong! Ya, they sell them, but not nearly as awesome. We made this Beer Pong Group costume out of standard plastic garbage cans. We spray painted them red and stencil spray painted the solo name (to make it official beer pong!). We used foam pipe insulator for the cup rim and put white felt around the rim and inside. We used belt material for suspenders and screwed them right into the garbage cans. For the ping pong balls, volleyballs are best (we ended up spray painting an old soccer ball too and it worked really well!).
We walked into the party in formation and threw the balls at each other and everyone loved it! By the end of the night the cups were being used for flip cup!
** Caution for those making this Beer Pong group costume: Do not allow others to join you in your cup, for you may fall and need to be rushed to the hospital for stitches, and it can hurt… **