Here’s a pretty wicked little DIY project:
And the video before that one, with more info:
For a quick text summary, Michael Graham Richard of TreeHugger has a good one written up already:
[Matt Richardson] used an inexpensive Raspberry Pi credit-card-sized single-board computer to create a very special kind of bike headlight that can dynamically project information on the road in front of you while still illuminating your way and making you more visible to other road users.
His prototype shows speed, but it could show almost anything that a rider might find useful: Maps, or turn-by-turn directions from a GPS program on a smartphone, or weather info, time to destination, distance traveled, proximity warnings if a car is getting too close, etc.
My take: this add-on looks quite distracting. I’m afraid to think of what some people might use it for. However, as Michael points out, it could be used for some very helpful notifications and such.
Can’t say I’d stick it on my bike, but seemed like it was worth a share.