Use Smart LEDs for Focus Assist
It's really cool how cameras can now shoot with acceptable results at super high ISO ratings like 6400. A few years back ISO ratings like this were nothing but a dream. (And before that Fujipress 1600 was the highest I ever used. Never saw a Fujipress 6400)
Alas, when shooting in the dark it is not an easy task to focus. And please forgive me canon users, but if you're a red brand lover, you're pretty much screwed).
Enter Malowz's invention - a strong focus assist that uses $10 in parts from deal extreme. Using a powerful LED and a strong reflector, Malowz build a hot shoe device that projects light to assist in focusing.
Here is the smarts, the focus assist uses an RF-602 radio transmitter to detect half and pull presses and it will only turn the light on when the shutter release is half pressed and then turn it off for the duration of the exposure.
Here is a video demonstrating the device
and a circuit diagram (way easier than what you may think)