Yes, seeing this product's very angular non-3d-printed yet-prototype design brought back memories of the days when the default portable hardware interface didn't always include a pointing device and thus there were these clip-on trackballs, like below.

Maybe some of the weirdest were things that looked like small mice that were linked and position-sensed by a bar linkage to the laptop. I can't find a reference to one tho, so maybe I'm mis-remembering?

http://xahlee.info/kbd/logitech_trackman_portable_trackball....