Wow... some of you are really immature on both sides of the table...
Sitting on MY site before check out and "helping" me pack? That's not going to happen. I will politely ask you to get off my site and continue with whatever I was doing. If my plan was to leave early, I still will. If my plan was to hang out at the lake/pool/etc then I will likely still do that.
On the other side, intentionally sitting until the last possible minute just to prove you are a jerk to the next guy? That is childish behavior as well... grow up.
What ever happened to civil decency? I've gotten to sites early myself. Usually if we are planning to be early we will call ahead and see if the site is vacant. If it is... perfect. If it isn't, we ask if there is a place to hang out while we wait. No big deal. If we show up early by accident we will usually try to find a restaurant nearby (or a Walmart/Target/etc if it isn't a meal time) and kill time there. If we show up and someone is still in their site (and we are early) we simply relax and wait our turn.
Intentionally pushing someone out of their site early is ridiculous. Intentionally sandbagging to delay someone else is ridiculous. Some people here really need to grow up. I am quite grateful that I have never encountered some of the posters here...