I wanted to do something interesting with my RPi and a 2.4" TFT LCD. Google Glass was hot in the news, so I've decided to hack something similar. The semi-transparent mirror was extracted from Eye of Horus Beamsplitter, and the projection lens is cut from a plastic 3x Fresnel magnifying lens. The box and mounting parts are 3D-printed from ABS. Head strap is for GoPro. One RPi USB port is used for WiFi, and second for 2.4Ghz small wireless keyboard/mouse combo. All together cost around 100$. I haven't figured out a good option for the power supply yet, and don't know if this thing can have a practical application. The display driver is fbtft framebuffer, so both text and (non-accelerated) graphical modes are possible, but with 320x240 resolution using X is not too exciting. Display brightness is sufficient if ambient light is not too bright.