Flexible pivots present numerous advantages such as no wear, no particle generation and predictable torque. In addition, the patented design presented in this paper adds high stiffness tunability, large angle, nearly constant radial stiffness over the entire range of motion, and infinite life capability. A design optimization software has been developed to generate within a few hours custom flexible pivot designs matching specific application requirements such as pivot angle, torsional, radial, axial, bending stiffness, maximal stress, and buckling factors. The flexible pivot design is an enabling technology for many applications and in particular for ultra-stable pointing mechanisms. A novel concept of an ultra-stable pointing mechanism using a flexible pivot is presented. It is shown with a simple Nastran model that the micro-vibration impact on pointing mirror stability can be theoretically decreased by 3 to 8 orders of magnitude in the 50-200 Hz frequency range, and by more than 9 orders of magnitude above 200 Hz in comparison with a design using ball bearings. The achieved pointing accuracy makes the need of a fine pointing mechanism unnecessary. The total mass, volume and costs can thus be drastically reduced in comparison to the existing solution today on the market that uses coarse and fine pointing mechanisms. A fully functional and motorized breadboard has been built and showed full hemispherical pointing range.