You didn't think that just because scientists have figured out how to isolate the genes that help fireflies produce light and use it to produce life-saving antibiotics, that there weren't still a hell of a lot of other applications to which these little bugs might be put to use, right?
Consider the fact that light is energy, and since the energy that goes into producing the light at the tail end of fireflies comes from ATP, and ATP is found in all living organisms (I know, high school biology flashback), now we have ourselves a little life-detecting test that can be used even in outer space exploration. Voila!
Fireflies contribute to the accumulation of knowledge through their butts... how about you? :)