Samsung has been awarded a patent on a method of sending an SMS to a handset then being able to later send a "delete" command to the same phone to erase the SMS from the handset memory.
The patent is apparently aimed at people who mass broadcast messages and accidentally include incorrect people in the mailing list. We obviously can think of more probable uses for the technology - such as quickly erasing those embarrassing messages you sent the night before when rather drunk.
Unfortunately, the patent states that if the recipient had read the message, then hungover and presumably, panicky people cannot send a delete message and hope the recipient puts the message down to their imagination. Oh well.
You can read the whole patent here - http://v3.espacenet.com/textdoc?DB=EPODOC&IDX=US2005124360&F=0&QPN=US2005124360"
Posted to the site on 21st June 2005