I've used the goLITE BLU device for just over a year now and have found it to be really effective for giving me more energy. Use cases: full blast soon after waking up to reset my circadian rhythms and then on a lower setting later in the day. (You obviously need to be careful not to use it too late in the day as it will inhibit the synthesis of serotonin into melatonin.) I would describe the energy boost as subtle, but effective and long-lasting.

That said, it's way overpriced. You could make your own device for MUCH less. Basically, any blue leds operating around 470 nm, which are pennies apiece on digi-key, would work. Wire up a whole bunch in parallel, put them behind a diffuser and you're good to go!

I've looked at that as well, but one of the reviews scared me away: http://www.amazon.com/review/R33CBCI3HRGKDJ/ref=cm_srch_res_...

Instead I'm going for exposure to any light in the morning and breaking the fast with a small snack.

Googling for the quoted text in the review reveals that the original source appears to be the website of a competing product. I cannot find the article in Science which is supposedly referenced but not cited.