Some of the following are great examples of outdoor advertising, specifically billboards, at their best.
1. Bic Razor
Source: Say no to crack
2. The Economist
Equipped with a sensor to light up when people passed underneath it
Source: Cherry Flava
3. Cingular
Source: Ad Freak
4. Gain
Part of the Irresistible Scent campaign, this 3D billboard has garments hanging and people climbing towards the fresh scent.
Source: Say no to crack
5. Adidas
Yes, very creative to even be considered a billboard, but this massive 3d advertisement was placed at the Munich airport for the 2006 World Cup.
Source: Jon Lee