As touched on, networking is key. The old saying is "it's who you know", but in fact it's who knows you. And it can be quite passive, as simple as showing up at a local jam and letting people hear what you do. Most of the time, there are working players hanging around and participating, and even if they aren't looking for someone at the moment, they'll take the names & numbers of the players they like. I've done hundreds of gigs with a dozen groups as the result of innocently sitting-in at a small jam near my home. If possible, visit several jams a week on a regular basis. You'll build friendships and credibility without much effort, and it can pay off well beyond that scene.
You can try the various musician/drummer referral sites, I've signed up with more than a few, and actually got one response after a few years. But it netted a fun, decent-paying monthly gig whenever I'm home. Don't pay for such services though. I don't believe that they're any more effective than the free ones. Google 'musician referral los angeles' and you'll see the kind of sites that result. Substitute your city/metro, or simply try 'musician referral'.
At the risk of opening the door for non-drummers to post here, you might consider joining and posting in guitar, bass & keyboard forums, as they are the kind of players likely to hire you. However, knowing how cynical and merciless we forum types tend to be, you'd better be first-rate before you put yourself out there, or they'll beat you up for even trying.
I haven't used Craigslist for soliciting work, and I don't personally know anyone who's admitted using it, so I don't know if it's effective. Is it free to list? If so, it certainly couldn't hurt and is a good way to target the areas you want to work.
Also check out local weekly papers with free or cheap personal ads.
Make sure you have a good web site. MySpace, facebook, etc are nice and free, but they're not substitutes for web sites and should not be relied upon exclusively for a web presence. Get your own domain name, which is what 99.9% of pros online do. However don't ignore the value of the social/media networking sites, you can use all to your advantage.
The thing is, you never really know who's going to see you or your name out there, so make sure you've got good exposure. Nobody can hire you if they don't know who you are. And also make sure you treat every public playing opportunity - a local jam, for example - as an audition. It's not the time to cut loose, you can do that at home. Play a jam like you're playing a gig, and always be professional. Those are the guys who stand out, and get the gigs.
Good luck!
Bermuda