If all you get are scams, and you've reposted it a couple of times (each time waiting for at least 3-4 days), then it may be just that you're asking too much for whatever you're selling. Either that, or SLO just doesn't really use craigslist that much.
Craigslist is funny, as the same posting may get 10 responses one week, after getting none the week before. As a seller, the best rule is to just price it fairly, and not get impatient. Oh, and expect people to flake out, and set things up so that when they do, it doesn't impact you much.