cereal because the cereal is going to draw people into the room, and is a pretty mess free snack.
comfy hanging chairs to make the room more inviting and confortable
nanoleaflights to give the room some character, and this way the room is more intereting.
A sofa to make a comfortable sopt for doing work.
A small table to store things, and place the interactive projector.
An interactive projector will open up a myriad of new opportuniites for compsci students to make cool projects that are creative and out of the ordinary.