Are you aware of the Rosetta project (http://rosettaproject.org/about/ http://rosettaproject.org/about/)? They claim their Rosetta Disk will "easily last and b

Are you aware of the Rosetta project (http://rosettaproject.org/about/ http://rosettaproject.org/about/)? They claim their Rosetta Disk will "easily last and be legible for thousands of years". If humanity was sent back into hunter-gatherer mode for a few decades, the Rosetta Disk would be invaluable in unlocking access to other material this new civilisation would come across (assuming they share at least a passing familiarity with one of the 1000 human languages the Rosetta Disk encodes information in). Thats the closest I've seen to what you talk about.