New Scientist | Mobile Phones | Write here, write now

Pinning messages in mid-air, using the location's Global Positioning System (GPS) reference, could become the next craze in communications. The messages are not actually kept in the air: they're stored on an Internet page. But that page's Web address is linked to coordinates on the Earth's surface, rather than a person or organisation. As you move about, a GPS receiver in your mobile phone or PDA will check to see if a message has been posted on the website for that particular spot. If you're in luck a snippet of info-left as text or a voice recording by someone who passed there previously-will pop up on your screen or be whispered into your earpiece.