Twincam - hybrid pulley-pushrod systemEdit
Vincent "Prop-Er" of the Netherlands came up with a really innovative hybrid pulley-pushrod system he called the Twincam, that he put into use on his Slopium glider prototype. It uses two elliptical pulleys that are connected via string to a pushrod. The elliptical pulleys provide mechanical exponential, allowing 180º rotation while still retaining high precision around center.
Here are videos demonstrating the Twincam mock-up, as well as in action on Vincent's Slopium:
This same solution ended up being used later in Shane Spoor's very inspiring Fluid composite ultrabat build, where it was used not only for elevator but also for 180º rudder actuation: