I thought having a movie party was such a cool idea.  My sister's son & my son are very close to the same age so we had their party together.  I sent invitations with a movie theater picture on it. I gave each child fake money at the door with my son & nefews picture on it (made on computer) .  I made a concession stand for the party with a desk & put my nieces in charge of concession. They used a toy cash register & money drawer.  I got some empty candy concession like boxes at walmart. I just asked for them.  I filled them with small candy bars.  We stuck lollipops in a square of styrofoam purchased @ walmart. I bought a big jar of pickles to sell. We had nacho's (canned nacho cheese) kids love it & its only about $6 for a really big can & popcorn with butter poured on top ofcourse. I purchased popcorn bags & nacho trays @ sams club.  We also served soda in styrofoam cups with lids I bought at the convenience store for 10 cents each.  Some will let you just have a few. It is very expensive to buy these in bulk so that was my best bet & it went w/ the theme so well.  After the kids purchased food itens candy drinks & movie tickets(roll of carnival tickets)they sat on the futon in living room.  I decorated the living roon with black fabric to darken the room. I had two sets of white rope lights going straight from the middle of the futon to the tv to act as an isle. It was really cute. I rented the lated movie out on video. Each child took home a cartoon movie ($1.00 each from walmart) & a mini bag of popcorn wrapped in ribbon. The kids are still talking about it & I got alot of my ideas from   birthdaypartyideas.com thanks