Stuck playing on a crummy system and want to see how the Übermensch play Skyrim? Or, conversely, do you own a killer rig and want to see how the peasants make do?
There's a site for that. Nvidia have made this handy interactive slider, which lets you quickly and, in some cases, dramatically see the difference between playing Skyrim on low and high settings.
In case you can't see them (low is on the left), check out the barn. And the textures. And, perhaps most importantly, the number of trees.
Skyrim Tweak Guide Comparison [Nvidia, thanks everyone!]