I have used craigslist alot over the last 3-4 years.
Here are a few tips.............
1) Sign up for an account. This is so that you can keep track of each of your ads and it also makes it easy to recycle.
" Did you say freeee?"
2) Recycle often, most people are only looking at what's on the front page of the REAL ESTATE section. This is easy when you have an account. Its also important to make your ads appear uniform. That way you become a trusted part of the craigslist community. ( clicks from the same people over and over beacause they know what they are going to get)
3) Cross-post in all local areas that apply. This is something that I have done in the past because of where I am located. There are three craigslist sites that people from the central valley post on: Stockton, Modesto and Sacramento. There is a technique to this. Craigslists requires you to change the look and content of your posts slightly as to not look like spam.
Monitor your craigslist "traffic"
5) Use links and promote mult-homes in one post. (using a generic html code for bottom of posts)
6) Make ads pretty generic so that you can change around easily recycle.
"woo-hoo, generic"
7) Use craigslist more to promote traffic to your websites then for direct leads.
9)
http://www.postlets.com/. This is a free way to crosspost onto similar sites that also have merit in the web 2.0 world. this will single handedly get you onto Trulia, Google Base, Oodle, Backpage, Edgeio, ByOwnerMLS.com and
a few others I never heard of. By the way did I tell you all you have to do is put in the MLS # and it pretty much auto-populates the ad for you, how awesome is that!
10) Use a teaser, to create a click over. I will leave information out inorder to get interested prospects off of craigslist.org and onto
http://www.tracyhomes.com/.
"tease me"
11) USE HTML on your ads and take control of how they look. There is a lot you can do with a craigslist page.
12) look for examples of good ads in SF craigslist. The cutting edge posts are usually in SF or NY.
I find craigslist most effective on the rental side. I find that you generate a good number of leads but usually very low quality. You get a-lot of treasure hunters and scammers. If you are not good at spotting a scam then avoid craigslist. Craigslist is not for the naive or gullible. Like I said I used to really work craigslist but found the leads to be not so good across the board. When I have a rental I always use craigslist though, that is how its done now in California.
WHAT IS YOUR TAKE?
-Brian Barringer -REALTOR®- Tracy, CA Real Estate 
;)
;)
thanks for the info--mike