I understand what you are trying to say Eps, but can I put a stick in the "Some stuff will not last" theory some anthropologists have regarding sensitive constructs?
Let's take modern stuff for example - a harddrive. It stores data, and data is the reason we have the harddrive. In 600 years from now evidence of a hard drive will still be around to suggest some sort of technology, sans the data it hosted. Along with all the other stuff we have like optic fibres, cpu's chips, etc etc etc - not everything in the ensemble of technological devices we have today will still be around in 600 - hell even 5000 years, but there will be a lot of traces of some sort of industrial and technological advancement in our species.
The Mayans, unfortunately symbolized stuff they saw around them and from the skies. They kept very primitive record of stuff and it only took a bunch of anthropologists and astro quacks to sell another dooms day prophecy and they also did a great job at securing themselves 15 minutes of fame on the Discovery Channel.
The only good thing the Mayan did was invent Tequila... um, I'm sorry that was the Aztecs. Damn Mayans.