Toronto artist Posterchild recently took a break from installing art in NYC phone booths to propose to his girlfriend. He popped the the question by appropriating a sign reserved for ad space above a Manhattan subway stop. Posterchild writes:

She thought she was just helping me out with another street art project; I kept this covered until after it was installed and after the unveiling I was expecting some kind of reaction- but it took a little while to convince her that this was a proposal for real, and not just some art project!

And she said yes! Congrats!