excersice bike with doppler effect speakers dependant upon pedalling speed.
pixelated visa photographs rendered live but too close to see… filmed and shown on screen at suitable distance.
idea #3 (albeit an old one)
a tv as a pendulum, with an image/film reacting to the movement of the monitor… eg always level or other manipulations. need not be technologicaly fiddly… just a bit of clever filming.
fake light bulb fittings made with customised light bulbs and sticks instead of wires presented upside down.
LED mosaics shapes ; first simple one maybe a heart presented in dark nasty urban spaces.
using eyetracking software, create movement in everywhere but your diresct line of sight, so only in the periphery vision. (thinking 9/2)