I just read "Digital Life" and saw this article about a high pitched ringtone that adults cannot hear. The technology was first used to drive kids away from stores if they linger for too long but it has been turned into a ringtone that can be used in school that is too high pitched for teachers to detect. Really interesting. Doubt, the adults can't hear, I don't think I really like that ring tone. Goodness it is so high pitched and irritating to the ears. To those who want the ringtone go to this webpage
http://www.nytimes.com/2006/06/12/technology/12ring.html?ex=1307764800&en=2a80d150770df0df&ei=5090&partner=rssuserland&emc=rss Just click on this link. One thing, it does not work on Nokia 6230. Sad case, when played on the phone, the pitch is lowered somemore. But it does on Samsung, on my brother's hp. Tried that on my mum and it works. Haha