My father always remarks on how unless society carefully archives its piles of electronic data, future archaeologists will be able to gather little information about our civilization.
Though technological advancement has permitted the invention and use of more sophisticated data-storage methods and devices, the durability of these methods and devices have decreased significantly - logarithmically, in fact.
Consider the following data-storage methods:
Stone lasts for
thousands of years - that's why there's still standing remnants of past civilizations and that's why we've been able to discover and interpret ancient inscriptions on stone tablets or hieroglyphics.
Paper lasts for
hundreds of years - thus the possibility of existence of the classics (what would we know if no one had ever decided to write down their ideas instead of just pass their stories on by mouth?), etc., and that spicy/musty smell of used bookstores. (Sniff...mmm....)

But what about
electronic devices - disks, CDs, DVDs, hard drives, and data sticks, etc? These devices have a life span of
decades, if that. DVDs, CDs,...despite their obvious advantages, they all degrade quite quickly. And besides that, consider that 30 years ago, if a TV or radio broke down, you'd bring it to a repairman. Nowadays though, it's cheaper (and much to the benefit of the corporation that makes the products) for you to just throw out your TV or computer or car and buy a new one because these devices aren't designed to endure. If there's anything left for future archeaoligists to find, it'll be huge piles of hundreds of thousands of invincibly plastic computer monitors which were responsible for putting so much lead into the ground. There'll be archeaological layers of garbage.
Furthermore, technologies now change at a rapid pace. If I gave you a diskette from 10 or 15 years ago, would you, or more importantly, your computer, know what to with it (or have any use for it)? Which goes to say, in 15 years, if someone gives you a piece of data from 2006, will it be completely foreign and useless to you?
Everything that survives will be virtual. If this Huge Cyber Entity called the Internet continues to evolve, then perhaps the archeaologists (if they haven't died from water poisoning, climate change, or a nuclear meltdown)
will discover something of this strange and revolutionary era......a mish mash of millions of porn sites, blogs, strange news reports, and even stranger things, like broadcasts from YouTube.com...
"The Scowls" and
"The Scowls Part2". (These videos are quite strange, I suggest you check them out.) What else can you find on YouTube or the internet that might make it to the future archaeologists? (Hopefully Vogons will come and destroy the Earth and save us from thinking about all this)
Comments
To reach this technological stage will take enormous understanding of the potential of data storage, near perfect efficiency will need to be attained and here is where our data problems will be saved. Imagine inscribing all the data ever created by mankind in the quantum spin of a handful of atoms. Assuming the stability of the quantum system can be maintained at levels relative to that acheived naturally (i.e it would take longer than the lifetime of the universe for your average proton to breakdown) this data will be eternal and last as long as the atoms encompassing it exist in a well balanced entropic oasis (such as our solar system).
Maybe this data could then be blasted through a wormhole or such like into other universes, thus spreading our knowledge off into future alternate realities....
Maybe I've gone to far.