I ride to work year round, and use a Blackburn X3, it's an LED light and works great. I think I paid about $125 for it a couple years ago. I put it on flash mode when in town as there's enough light coming from street lights that I don't need it to see necessarily as much as to be seen Cars can't miss me. I think some think they're being pulled over by a bike cop.
It has both a handle bar mount and a helmet mount. I use the helmet mount almost exclusively. I can look at an oncoming car and get it's attention better, usually a car getting ready to pull out in front of me.
It has a smart charger that will keep it charged up indefinitely, only takes 4 hours to charge fully, I don't have to worry about taking it off the charger, it won't over charge. it'll last 3 hours at full capacity and I think 5 hours total. It has three power levels and flash mode, on flash mode it'll last like 15 hours.
My only complaint is the battery pack is a little bulky. I keep the battery in my coat pocket when commuting and in my rear jersey pocket when riding trails. Yes, it has enough lumens to light up a trail.
I also have the X6, it has two lights, one direct beam and one wide beam. I've been mounting it to my handlebars, with the battery strapped to my top tube. And I use my X3 on my helmet. I only use this set-up for night-trail-riding. It works great. the trail ahead of the bike is always lit up by the handlebar-mounted lights, and I can wherever I turn my head is also lit up from the helmet light.
Pricepoint had the x6 on clearance this last spring for $100, a smoking deal. I think it's been discontinued and the X8 has replaced it.
A friend of mine just got the Blackburn X4 and as I predicted, the batterypack is smaller and the light output seems to be the same as myX3.
Hope this helps.
BTW, I've been away from Mud most of the year and I too was suprised to find this section, as well as several others.
Dan