Tired of having to tap (or, let's be honest, mash) a boring old button to cross the street? Los Angeles artist Alfredo Adán certainly is. He recently created Walkbump, a project that covers crosswalk buttons with casts of a fist -- as you'd guess by the name, you have to fist-bump the button to signal your intentions. It's a "simple" hack (even if the construction process isn't), but it does add a friendly flair to your trip across the road. You're not so much telling the traffic light to change as asking it nicely. While this isn't as clever as some crosswalks, such as one that plays Pong, it does bring some much-needed humanity to the urban landscape.