This guy commissioned New York-based graffitti muralists to paint an entire wall in Manhattan's Lower East Side for his lovergirl. (She said yes. Thank god.) Grand gestures like these are probably as old as marriage itself; what's weird is the concept of a personal decision in the form of community art. It's obviously a sweet gesture, but I wonder if the mural's neighbors really want to stare at someone else's marriage proposal every time they walk down the street.
Let me also add that this YouTube video has quite a hilarious (and incongruous) soundtrack.