Normally, Memorial Day weekend is wrapped around the last days of school rather than coming after it. I would ordinarily have given a lesson based around this article from Mental Floss back in 2008.
If you're a former (sniff) student of mine, give it a read. It's a good indicator that this weekend isn't about barbecues and the Indy 500 and--in my case--infinite graduation parties. It's about something really cool.
I hope you're all having a good summer so far, and that you'll take some time to remember what it's all about tomorrow.