Good thing about this is that its free and can be done in less than a minute, otherwise it might not be worth doing to be honest.
*DISCLAIMER* I used two mostly charged energizer lithium batteries and the LED hasn't broken even after holding it on for a minute, so it should be fine. HOWEVER, I am in no way responsible if this breaks your nitefinders LED (its crap anyway, so don't get too upset). ALSO it will use up the batteries a bit quicker.
Simply wrap a small piece of rolled up tin foil around the two legs of the resistor on the little circuit board like so:
![Posted Image](http://i49.photobucket.com/albums/f263/burntcustard/RIMG0036.jpg)
This makes the LED considerably brighter, making it show up a bit better. Useful if your one of those people that likes to have a dot on the wall showing about where there dart will *probably* go.