Project-based learning has been around for some time now. Engineering activities are relatively new to the education space. These two fields often go hand in hand as engineering challenges often require essential PBL skills such as applying academic content, working in teams, and reviewing progress consistently.
If you are on the hunt for some cool PBL challenges with an engineering twist, check out Instructables. WYE Lance is the author of these units and he provides video instructions for more than a dozen low budget engineering projects. YeehA!