In the spirit of peace, love, and general awesomeness, I high-five you!
National High Five Day falls on the third Thursday of April each year, which falls this year on April 19, 2007. The holiday originated at the University of Virginia in 2002, and has since spread across the nation, and around the globe.
Imagine that while on your way to class, you pass a dignified looking middle-aged man in a suit. Instead of noticing this respectable pillar of society fifteen seconds or so before your interaction is fated to occur, and lowering your head to avoid his disapproving scowl, you and the businessman simultaneously raise your hands and wordlessly high-five. You both walk on, and likely relate the story to whomever you eat dinner with that night.