I used to walk past the De Bono centre on Melbourne's Collins street every day. During that time I also pulled out Dr De Bono's thinking hats model in several workshops.
How is it useful?
Once you have a team performing strongly as a group you tend to get a bit of groupthink. The thinking hats apply a structured way to get people to think differently about a problem. This helps break out of that groupthink so that you can get a bit more creative about identifying and solving problems.
Take a look at the below slide deck for more information.