Netflix -- $14/month
Data projector and laptop computer -- $0 (borrowed)
Really good homemade pizzas and snacks -- $65
All my best friends and their kids having a great time at our Drive-In Movie Picnic Party -- Priceless!
I can't take credit for the idea -- I got it from Everyday With Rachael Ray. It was a big hit! The kids played on the jungle gym and watched the film, while the grownups relaxed, talked, and had a good time watching a funny movie (RV) under the stars.
We'll definitely have to do this again sometime.