Enjoying my bike with 6 strips of WS2811 RGB LEDs driven by an Arduino on the front wheel. LED programs can be switched on the go with sequences of brakes or hitting the handle bar on the side, which are detected by the sensor board in the wheel. Instructable here: instructables.com/id/Bike-wheel-WS2811-LED-effects-with-Arduino/
The LEDs can show text, images or animations but this is not in the video because the Persistence of Vision effect is not visible when recorded with my point & shoot camera, or a few phone cameras I've tried. This was recorded with my CHDK-equipped canon point & shoot with all default settings and no processing. I need to try out the videxp3.lua script for CHDK next time, it might be able to force longer exposition times. When looking at the Monkey Lights video (which looks great on video despite only 4 LED strips), I notice many of the shots with the lights are half-or-so frame rate, which I guess lets them use longer exposition per frame. There also seems to be a very slight motion blur effect, which works if the camera moves together with the bike, but I mostly have static camera so it wouldn't make any sense.
The LEDs really are as bright as they look here, at night, and can still be seen in daylight. This is all at about 1/3rd the full power.