Approximately five weeks till school starts. . .

School starts in about five weeks.  How are you keeping your kids brains working this summer?  I have been a bit slack this year about encouraging them to read and making them do educational stuff.  They have been busy with camps and going to the pool so they have not been completely lazy.  I am afraid their brains may be turning to mush though.   We have been having good dinner conversation about world events and we are going to use our vacation as a learning experience.  We hope to check out a few lighthouses while we are at the beach and visit a few other historical spots along the way.  What are you doing to keep your kids brains from going to mush this summer?  I would love to hear your ideas.