You may have thought that it bit the dust last year when Circuit City killed its pay-per-view DVD format, Divx, but laser tech company SpectraDisc has re-opened the files on throwaway DVDs, abeit in a more Mission Impossible style. The company has developed a special coating for DVD discs that starts to degrade when the DVD laser touches it. How long this process lasts depends upon the thickness of the coating, and the time limit can currently last from minutes to three days. When the time is up, the chemical process is complete and the user ends up with an unreadable blue disc. The product is aimed at the same ‘rent then throw away’ market as Divx, but suffers from none of that formats problems with special players and issues of personal liberty. The new discs run on conventional DVD players and do not use phone lines to inform retailers of viewers’ habits. Because of the nature of the technology, the process could also be applied to music CDs and even CD-ROMs.