Actually, this application of lasers would hopefully be in use a long long time before we ever had to use lasers to stop ballistic missiles. (I don't ever want to have to rely on a beam of light being the only thing between me and a ballistic missile). Nathan Myhrvold (of Microsoft fame) demonstrated at TED a laser (built from parts scrounged from eBay) capable of shooting down not one but 50 to 100 mosquitos A SECOND. Not only that but the system is "so precise that it can specify the species, and even the gender, of the mosquito being targeted". Currently, for the sake of efficiency, it leaves the males alone (because only females are bloodsuckers, ain't that true!). Estimated cost? $50!
Maybe that's too expensive for use in preventing malaria in Africa but I'd buy one in a second! You can see it in action at: http://intellectualventureslab.com/ (Site was very slow but maybe it's because I am connecting from Thailand).
Until mosquitos evolve tin foil hats, we'll get the upper hand! (Can you tell I really really hate mosquitos?)