I originally posted this on another thread, but then realized this topic should have it's own thread, as it should (hopefully) become a good topic.
On my last gig, I did a series of headshots with my favorite local model.. with virtually all of the lighting being provided by two 10w Power LED's from Home Depot, being sold as an energy-efficient replacement bulb for recessed can lighting. They were $20 each, so I'm sure you can get them for $10 or less online shopping around a bit. The only addition was a 150w modeling lamp at 50%, through a softbox, to provide for a little hair lighting and a bit of dramatic contrast, from a few feet above and to the right.. We were featuring her eye makeup. All of the facial and balance lighting is those LED's. Suffice to say, these are very viable and nearly indestructable studio necessities from here on in. Cheap is critical for me.. to be honest I try to break even with my costs, and barely most of the time. I'm not a Pro... I'm a skilled amateur at best.
Here's a scaled B&W headshot from that series. The thing is, the LED's were great to work with- we could hand-hold them by the base of the bulb comfortably for up-close lighting. The color temp is a very pleasant warm white, in fact, color balance correction was needed in some shots because I had absentmindedly left the camera calibrated for flash color balancing. The shot was post-processed into B&W using Photoshop Elements. It was taken with a Canon 350D, ISO 200, f/1.8 50mm Prime ("Nifty Fifty" rev 2. Under a hundred bucks new and worth it's weight in gold). Though I've scaled it here for posting, the shot is uncropped, the only post processing was B&W downconversion by Photoshop Elements.

Now consider that lighting is just two 10 watters.. coming from LED's which are probably (will be checking internals) running a much more managable voltage internally.. a voltage which could be supplied on-the-go like with batteries (Pb gel cell or Li). I'm envisioning either a PVC frame with directable LED heads, or maybe even a ring light on roids.. PWM control and possible inclusion of some RGB elements for color balance and accent light. As you can see on the side of the bulb unit I purchased, it's a CREE emitter inside- the price on these is dropping like a rock.
Not only is the light very workable, it's low enough power consumption to make portable studio lighting a reasonable idea.. Thoughts?