Etsy seller boonerings has a $385 titanium “utility ring” with five in-built tools: “a working bottle opener, a straight blade perfect for cutting packing tape or fishing line, a serrated blade for tougher things like nylon strapping or those tough to open electronics heat sealed packages, a saw for cutting plastic and wood, and it has a comb” (the comb is recommended primarily for moustaches).
The Man Ring: Titanium Utility Ring
(via OhGizmo)