It's the oldest story in the world. One day you're 17 and you're planning for someday. And then quietly, without your ever really noticing, someday is today. And then someday is yesterday. And this is your life. -One Tree Hill
This simple motivational poster uses the negative space inside the "D" and the "O" to incorporate more letters to create a straight forward message. This is a great example of how negative space can be effectively used to bolster a design's message.