Lazer makes helmets with integrated lights.

I don't ride in pace lines so I use powerful lights. Epsecially for commuting. I have two Magic Shines in front and two PBSFs in the back. I also have a cheap blinkie in the front so I can turn the MS lights off in bike lanes as not to blind oncoming cyclists, but I ride in the city so there is enough light in bike lanes. Even if I ride with a club we're spread far apart and hardly ride in darkness so I still use PBSF in the back and some average blinkie in the front.