DIY Bicycle Spoke Light Kit. $37.50 gets you a bike kit that will make you the envy of your neighbours and friends. Or ex friends. Whichever comes first. More here.
The spokepov kit includes parts and circuit board for one basic configuration SpokePOV with 1K of memory (for one static image) and 60 high brightness LEDs (30 on each side). Available in red or yellow in both BMX (6.5″ long) or MTB/Road (9.5″ long) and blue in MTB/Road!