If you're a homeowner, you have to keep a tube or two of Loctite Power Grab around. This stuff is amazing. I was putting up some solar-powered outdoor lights and in a few places could not locate the solar panels on a drillable surface. Without screws or any other fasteners, Power Grab sets quickly and stands up to heat, moisture, bugs, dirt, birds, you name it. Also adds strength in closing gaps where you might otherwise use weaker caulking. Cheap and effective, it's the new duct tape! (via Aubuchon Hardware)