- Eye-tracking is highlighted as the lowest-latency, most reliable non-invasive brain–computer interface for users with intact vision, outperforming EEG-based BCIs in everyday use.  
- EMG experiments are discussed for both foot-toe control (minimal interference with other tasks) and upper-back “wing-like” extra limbs; the latter is considered noisy but promising because back muscles can move independently of arms.  
- Open-source hardware references include a Thingiverse 3-D-printed analog foot controller (thing:3779666) and rope-based encoders as low-cost, DIY input devices.  
- Facial-needle EMG was mentioned as a short-term hack but dismissed as unsustainable for long-term BCI use.  
- Off-the-shelf game controllers (analog sticks + 9-axis IMU + buttons) are praised for delivering rich gesture sets without custom electronics.