Hot on the heels of the news that Cooper-Menvier/Fulleon is to take on global manufacture and distribution of the Mosquito, my server logs show that someone found this site through looking for mosquito download mobile phone free high frequency. Now, he or she might simply have been looking for a ringtone that sounded like a mosquito. Or, more interestingly, a 15kHz+ ringtone specifically designed to drive away teenagers along the lines of the Mosquito device itself. What would the effects be? I guess you wouldn't know your phone was ringing unless you were in the age group that can hear that frequency range. But if you were to use it to drive away young people (for whatever reason), you could do it very discreetly. You could even keep the phone in your pocket, continuously playing the high frequency sound, to produce an exclusion zone around you. Like a portable hand-held sonic mole repellent, but for a particular age group of people against whom you want to discriminate.
Such an application has probably already been patented but if it hasn't, it's in the public domain now!