When I search Craigslist I prefer to let Google do the work, as shown below. Typing such search strings directly into the Google Search field — or into the address bar, on Chrome — garners one great results.
honda cruiser -trailer “good condition” site:milwaukee.craigslist.org
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.