I've followed this guy for a while. I think he "retired" in his mid 30's. http://www.mrmoneymustache.com/
There was a lot for sale about 3/4 mile from where I live. Someone took down the trees. The lot was next to a few really big houses. We thought, oh another big house coming in. Instead, the people have parked a pretty good sized RV on the lot and are living in it. Their kids go to the local school. I'm wondering if they are saving to build a house on the lot or just saving for retirement or whatever. They have been there for about a year so far. Maybe they just buy lots, live on them for awhile and then sell them for a profit and then go buy a bigger lot. Time will tell.