In this video den talks about using the Cineroid.com LED light. This is a lightweight battery powered light with options to switch between daylight and tungsten heads in a matter of seconds.
The light is dim-able from 0-100% and comes with a hot shoe attachment and an NPF 570 battery and charger.
The output is super bright and has a CRI of over 90 making it very colour stable and consistent. It has a built in fan also to keep the heat-sink cool and further maintain colour accuracy. You have the option to switch the fan to off/on or auto if you are recording sync sound and want to lose the fan sound although it's barely noticeable.
It's very durable and offer great flexibility for location shooting.
I used it recently on musicvideomasterclass2011.com which you can watch here:vimeo.com/32438160
For more information and to get a report on 'The 5 Mistakes Made by Aspiring Film Makers When Buying Gear and How to Avoid Them' go to fstopacademy.com