I used to buy tons of stuff off of craigslist. The only problem is - I live near 4 different craigslist locations and every time I need to find anything I have to check 4 different sites.
The problem I have with all tools listed here - they don’t let you choose which sites to search. Come on, I don’t need all locations - I only want to look in a 10-20 miles radius !
Finally, here’s the site that does it all - search by ZIP/area code, search within several miles radius, show picture previews and even replying to the posts without having to register - http://www.craiglook.com