You thought I was going to say bang, didn't you? Well, I fooled you!
Laura Numeroff's If You Give a Cat a Cupcake is the perfect book to kick off summer vacation with your story time regulars. Cat is one active little feline. (Note: Here's my review of the book from last summer.)
After reading the book, you could have the kids make summer passports or you can make a checklist for them. They can check off the things they do that Cat did. Here's a sample list:
 Go to the beach (Swim, Build a sand castle, Look for shells)
 Go to the gym (Run/Walk on the treadmill, Lift weights, Learn karate)
 Go to the park (Take a rowboat ride, Ride the merry-go-round)
 Visit a museum
These activities can be adapted to fit any age group and locale. Let's all go have some summer fun!