One thing I just LOVE about being a teacher is getting all the federal-type holidays off. I mean, I think just about everyone gets this one off, but I also get MLK Day, President's Day, etc.
In any case, think of a veteran (calling one up and saying "thank you" is even better). Share some good times with friends and family. Grill some meat (or veggies, if that's your preference). Let the kiddos run through the sprinkler for awhile. Dig into some watermelon. Call it a day.
Those are pretty much our plans for the holiday.