Machete considered this to be one of his greatest inventions, Machete's Elastic Wonder. It's a stylish rubber band. According to him, there are 999 uses for them. The key is to figure out what they are.
Carmen and Juni did find many ways. Juni made it a stylish bracelet, which he later gave to the president's daughter. Carmen used it as a snapping weapon (on Juni), a switch binder, and grabbing the Transmooker.