I feel like this will be our era's version of Stonehenge. Hundreds of arrows, all pointing vaguely-but-not-quite West, with no discernable explanation.
Maybe the Olmec heads http://en.wikipedia.org/wiki/Olmec_colossal_heads or the Costa Rican stone balls http://en.wikipedia.org/wiki/Stone_spheres_of_Costa_Rica served a similar function.
This is one of my favorite things about the future, you never know how distant people are going to interpret what they find. Could you imagine some future anthropologist doing their dissertation on tewrking or memes. There are the thought that keep me going.
Lucky for them though, we currently document pretty much every contemporary cultural phenomenon, either by adding to dictionaries or through the internet. As long as the internet or records from now exist in the far future, there shouldn't be too much trouble for future generations.