Sugru self-setting rubber is something every do-it-yourselfer would love to have stashed in the toolbox. Self-adhesive and moldable by hand, it bonds to steel, aluminum, wood, ceramic, and glass, and comes in 10 colors. Fix frayed cables or cracked pot handles, or use it to make a tablet mount for your kitchen wall. There’s no end to its usefulness. Available on Amazon; $22.