Topeak MiniRocket iGlow

Press the power button at the bottom of this bike pump and an LED in its transparent tube shines a soft red light to reduce the odds of being rear-ended. Easily mounted to your seat post via elastic bands, the mount and Presta-valve pump install on your tubes in about five minutes. Though it seems flimsy, the pump stayed put during multiple rides in Los Angeles and Mammoth Lakes. Not meant to be used as the main source of illumination, the device does lighten your normal pack load and acts as secondary source of rear light. [$35; topeak.com]