Okay, this Revolight persistence of vision rim mounted bicycle light is groovy.
A tube of LEDs is clipped to the inside of each bicycle rim, with power from a battery packed near the hub and synchronization through a fork mounted magnet.
According to Revolight’s Kickstarter page, MSRP will be $220. A similar POV bicycle wheel light, Dan Goldwater’s Monkey Lectric, retails for $65.