The last time my family called a contractor, it involved remodeling the entire house, including extending the livingroom and converting the garage into a bedroom -- a proper one, not just a finished out garage. For pretty much everything else, we do it ourselves. This occasionally leads to problems -- for example, there is currently a large hole in the bathroom wall, because we redid it completely, right down to putting in a new tub, but then I had to move off to college before we could repair the hole we had to cut through the wall to put the new tub in with, and my dad and I are the only two people in the house who can actually do the lifting involved.
Other projects have gone better -- my parents tiled the livingroom, dining room, kitchen, porch, and one of the bathrooms themselves. We do our own plumbing, including everything from installing sinks and toilets to fixing problems with the pump. We also do our own electrical work, at least in as much as installing light fixtures and replacing electrical outlets counts as electrical work. We even do our own tree pruning each summer, and my dad and I built an awesome tree house when I was a kid, it was basically a screened in deck built six feet off the ground. I was really upset when the hurricanes came through in 2004 and knocked it off its foundations. Heck, the last time our washing machine broke, we actually diagnosed the problem, bought the part, and installed it ourselves. Doing it yourself saves a lot of money, even if it is occasionally frustrating.