I usually make sure that I celebrate my chilren's birthdays sperately even though they are only one month apart. But this year we ended up celebrating them late so I combined them.  Rent a dvd projector, staple a sheet to two posts and invite friends over for wine, cheese, and fruit to watch a movie in your back yard. After reading that I thought I could tweak that for a kids party. For the invitations I went to the local scrapbooking store and purchased car cut outs and packages of stickers that contained a bag of popcorn, candy bar, soda, and tickets. I also got some paper that looked like grass, and the night sky. On the front I cut out a small amount of the grass" for the bottom 1/4 and the rest was the night sky. I put one car on the front and then made a drive in sign: I and S Drive-In (Ian & Sophie). On the inside I covered all of the invitation with the night sky. I then cut out a yellow piece of paper for the "screen" printed with "Now Playing Ian and Sophie's Belated 2nd and 4th Birthdays...". I placed the stickers all around the screen. I went on line to Disneyshopping.com and purchase beach chairs for the children we invited. They were on sale and I only had 11 I needed to purchase. (I figured that I usually spend the same on goodie bags by the time I am done with them.) I used colored foam boards to cut out cars to attach to each side of the beach chairs. I used black poster boards to make the tires and then used colored pipe cleaners as the "hub caps" which attached the board to the chair legs. I also had to use a little tape to keep the top of the cars attached to the arms of the chairs. I had picked the chairs with each child in mind so I put their names on the cars. I placed all the "cars" in the yard facing the movie screen. For the concession stand I went to the dollar store and purchased plastic popcorn bags filled them with mircowave popcorn purchased variety boxes of candy bars from Costco and juice pouches for the "sodas". I put those on a table and gave each child play money so they could "purchase" their treats. For the front door I taped 4 foam boards together and wrote "I and S Drive-In .. Now Playing..Ian and Sophie's..2nd and 4th Birthdays". For the projector and screen I got lucky that my husband's brother works for a school and we were able to borrow a system.  I had actually purchase some white vinyl to staple to 2.4's for the screen. When everyone showed up (7pm) we had went ahead and had pizza for dinner. We had cake around 8pm. After the cake I set up the concession stand. The kids loved being able to "buy" their own treats and then go to their cars to watch the "drive-in movie". Most of the parents grabbed a chair and sat out to watch the movie also. After the movie we opened presents. Then it was time to go home and each child got to take their "car" home with them. It was a real hit.        .   "