Many folks swear by getting free or cheap stuff on Craigslist, but for me, it just isn't worth the hassle. This is partly because I live in a large city and most of the items listed on Craiglist at any given time will be a) already taken or b) too far away to be worth the effort.
I think that the kind of person who is most likely to have success on Craigslist a) owns a pickup truck or other large vehicle (for large purchases) b) is strong and has access to extra help (again, for large purchases) c) lives in a small city, d) has lots of free time to stay on top of ads and pick up merchandise, and e) is not picky.
I've gone to look at a couch I saw on Craigslist before and found it to be a real waste of time. The couch looked much nicer in the photo than it did in real life so I wasted about an hour driving back and forth to go look at it.