Not necessarily. If you have Firefox, open up whatever craigslist searches you want. Lets say I want to search for 240zs in Philly, and all of NJ. I'd open http://philadelphia.craigslist.org/search/sss?query=240z, and the others for NJ and use the 'bookmark all tabs' option to put them in a folder. Then just go to your bookmarks, find the folder, and click 'open all in tabs.' Not sure if that will work with other browsers, but it might, depending what features they have.
If that didn't make sense, I apologize. I seem to be having trouble organizing my thoughts at the moment.