Example Search String:
honda cruiser -trailer "good condition" site:milwaukee.craigslist.org
Above, we see my general search terms, including my desire for the word 'trailer' to NOT be included in the result set, followed by my desire for the exact phrase, "good condition", followed by the site I wish to search.
Note that I could as easily have typed:
and Facebook would have been searched. You can try it for other sites too, E.G.,
windows 7 important updates site:microsoft.com
Or, you can do it all more easily by going to http://www.google.com/advanced_search and typing the domain (site) name into the domain field.
In either case, you can bookmark your search criteria and click it at will. For example, if you are watching for a specific product to arise, on your regional Craigslist site, you can simply click the bookmark periodically to see what is available.
[Note: In searching for the original bookmark, related to where I first learned this technique, I'm thinking it was probably here, back in 2009: http://www.pcworld.com/article/162030/10_craigslist_tips_for_power_users.html ]