Greenpeace

Greenpeace are well known for their positive work for the environment across the world and they also have some pretty good designers working with them.

In this example below they have shown that clever wording can be effective design and doesn't need anything particularly complex. The design is not particularly eye catching but the placement is; When someone is holding something it is generally a lot more noticeable.
The Greenpeace logo can be seen across the bottom so that everyone knows what the design is about and the poster is immediately linked to a huge context.

In this example below, Greenpeace have taken advantage of an existing design which caught a lot of attention and that most people knew about. In this way they could ensure that it would be recognised and noticed and the link to the original design applies a sense of grandeur to the new design. 

The original design was a big deal because it was the first time that anyone had tried to advertise atheism and it caused a lot of controversy across the UK. 

The Greenpeace design borrows the same idea and changes the meaning: