I've used Craigslist to find 2 apartments, find someone to sublet one of my apartments to, sell all my extra furniture in Phoenix, and bought some furniture in San Diego. Definately go with your gut feeling - most people are normal and very nice, I've gotten blown off once or twice.
Also found a few jobs on there paying pretty well too...If anyone's college age girls are looking for work, try in the events section. I was a Miller Lite girl and various other beers for $25 - $30 an hour...found on Craigslist!
So, I've had really good luck with it. I try to make sure someone's home if people are coming over to pick stuff up though.