I did a double-take when browsing my Excel Sports catalog. L&M concocted a Li-ion taillight with amber side markers, USB chargeable, 35 lumens, reasonably light & compact, and has a passive reflector too. The flash mode is briefly shown in this video:
I'm a little underwhelmed at the "sine-wave" flash mode... the more you can differentiate yourself from the background, the better, and I would've rather seen a strobe-style flash. Anyway... anyone got any firsthand reports on these?