Search Every Craigslist Site at Once
If you're a Craigslist addict, you know the Holy Grail of the online classified site would be a way to search the entire site at the same time.
For whatever reason, Craigslist does not want you to do this. When the question of searching the whole site at once is posed to Craigslist discussion forums, the response is always "you can't," and the civility of responses goes downhill from there. It should be noted that searching the entire site goes against the culture that Craigslist attempts to engender. It was never meant to be an alternative to Ebay, a global online forum for trade, but rather a community-based forum for trade. Do not be surprised if your communications with people outside your area are ignored or you are treated as a scam artist.
So if you want to buy a car, find a job or trade antique fly fishing lures, and you're not having luck in your specific locale, you would search the San Francisco Bay Area region landing page, then New York, Great Britain or any other city, state, or country where cars, jobs and fly fishing lures are found.
It's a tedious and, now, unnecessary task. There's a workaround to searching Craigslist's entire world-wide offerings at one time...