Over on YouTube user Mile Kokotov has uploaded a new video showing his SDR frequency controller in action. The controller allows you to tune the frequency with a knob, which is preferred over the keyboard and mouse by many. In his video he shows it in action on the SDRUno software.
The controller is made out of a simple rotary encoder and a USB mouse. The rotary encoder is an EC16 (with no detents/clicks). It is connected up to the mouse PCB instead of the scroll wheel. Mile mentions that the encoder only cost him about $2 from eBay, and the mouse only $3, bringing the total cost of the project to only $5. More information and images can be found on his project page.