You can go to the movies for 50 cents as part of Cinemark's Summer Movie Program and for $1 at AMC's Summer Movie Camp.
Goodrich has a $1 program, and Regal has a FREE program! If you go, make sure you arrive early because the theater gets pretty crowded.
Here's a list of merchants that offer homeschool discounts, along with information on where you can obtain a free homeschool ID card.
Also check out Kysha's blog for a link to the Pizza Hut Book It program.
I just added a section on Affordable Homeschooling to my website where you'll find additional money saving tips.