South Korean mobile operator SK Telecom (Nasdaq: SKM) has finally brought something useful to the otherwise annoying world of ringtones.

According to the Korea Times, SK will next week introduce a downloadable ringtone that can be played on a mobile phone to ward off mosquitoes at up to a meter away. The ring tone is so high pitched that it is undetectable to most humans and household pets, although it does piss off hamsters and guinea pigs (see Hamster Bites Man).

The ringtone repels pregnant female mosquitoes -- the ones that bite -- because it mimics the sound made by the beating wings of a male mosquito, which are the last thing the ladies want to see when they have one in the oven [ed. note: that the technical term is it, Dan?].

Unstrung has done some investigation into the business of repelling creepy-crawlies using high frequency sound, and we think there's probably a market there for an enterprising startup. This is because different vermin -- such as cockroaches, rats, and insurance salesmen -- are scared off by different whines than the one that works on the mosquitoes. So you'll need a selection of repellent tones to ensure that you are completely pest-free.

Of course, if you just want to avoid contact with rest of humankind, Unstrung recommends a David Hasselhoff ringtone [ed. note: it's better than flatulence!].

— Dan Jones, Senior Editor, Unstrung